EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. In this sentence, 'had hidden' happened before 'arrived'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前就已经完成的动作。在此句中，「藏好（had hidden）」发生在「里奥到达（arrived）」之前。
By the time the movie started, we had bought our popcorn.
在电影开始之前，我们就已经买好爆米花了。
EN： 'By the time' is a subordinating conjunction used to introduce a time clause, meaning 'no later than the moment that'. It is commonly paired with the past perfect in the main clause to show a sequence of events.
中文： 「By the time」是一个从属连词，用来引导时间状语从句，意思是「最迟在…之时」或「到…的时候」。主句通常搭配过去完成时，以强调两个过去事件的先后顺序。
By the time she called me, I had already gone to bed.
到她打给我的时候，我早就已经上床睡觉了。
EN： In Western culture, surprise parties are a popular way to celebrate milestones or birthdays. Guests typically arrive early, hide in a dark room, and shout 'Surprise!' when the guest of honor arrives. The use of the past perfect tense here highlights the careful coordination required to pull off such an event before the person walks through the door.
中文： 在西方文化中，驚喜派對（surprise party）是慶祝生日或重要紀念日的常見方式。賓客通常會提前到達並躲在暗處，等主角進門時一起大喊「Surprise!」。這裡使用過去完成式，強調了在主角進門前，大家為了保持驚喜而進行的周密準備與協調。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before another action or a specific time in the past.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。
She had finished her homework before her mother came home.
在她母亲回家之前，她就已经写完作业了。
EN： The preposition 'before' is used to indicate that an event happened prior to a specific point in time (in this case, 'noon').
中文： 介词「before」用于表示某个事件发生在特定时间点（在此句中为「noon」中午）之前。
We arrived at the station before nine o'clock.
我们在九点之前就到了车站。
EN： In Western culture, baking a cake from scratch for a friend's birthday is a common and highly appreciated gesture of affection and effort, often associated with surprise parties.
中文： 在西方文化中，親手為朋友的生日烤蛋糕是一種非常常見且備受感激的表達關懷與心意的方式，通常與驚喜派對緊密相連。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before a specific point in time in the past.
中文： 过去完成时（had + 过去分词）用于表示在过去某个特定时间点或动作之前，就已经完成的动作。
They had finished the report by yesterday afternoon.
他们在昨天下午之前就已经完成了报告。
EN： The phrasal verb 'blow up' means to inflate something with air or gas. In the past perfect tense, 'blown' is the past participle form of 'blow'.
中文： 短语动词 'blow up' 意为充气或吹胀。在过去完成时中，'blown' 是动词 'blow' 的过去分词形式。
We need to blow up these balloons for the party.
我们需要为派对吹这些气球。
EN： In Western birthday party preparations, blowing up balloons, hanging decorations, and baking cakes are classic DIY activities involving friends and family to create a warm, personal surprise.
中文： 在西方生日派對的準備過程中，吹氣球、掛裝飾和烤蛋糕是經典的 DIY 活動，通常由親友共同參與，以營造溫馨且充滿個人心意的驚喜氛圍。
EN： The Past Perfect Tense (had + past participle) is used to describe an action that was completed before another action or a specific time in the past. In this question form, the auxiliary verb 'Had' is placed at the beginning of the sentence.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。在此疑问句型中，助动词「Had」被放在句首。
Had you finished your homework before the teacher arrived?
在老师到达之前，你已经写完作业了吗？
EN： The preposition 'before' is used to indicate that an event happened prior to a specific event or point in time (in this case, 'the party').
中文： 介词「before」（在……之前）用于表示某个事件发生在另一个特定事件或时间点（在此句中为「派对」）之前。
We arrived at the cinema before the movie started.
我们在电影开始前到达了电影院。
EN： In Western culture, writing personalized greeting cards (such as birthday cards or thank-you notes) is a highly valued tradition. It is common to prepare these cards before a party or social gathering to hand them directly to the host or celebrated person.
中文： 在西方文化中，親手撰寫個人化的賀卡（如生日卡或感謝卡）是一項非常受到重視的傳統。人們通常會在派對或社交聚會開始前準備好這些卡片，以便直接親手遞交給主辦人或壽星。
EN： The Past Perfect tense ('had hidden') is used to describe an action that was completed before another action in the past ('came in'). It emphasizes the sequence of events.
中文： 过去完成时（had + 过去分词，如 'had hidden'）用于描述在过去某个动作（如 'came in'）发生之前就已经完成的动作，强调事件发生的先后顺序。
When the movie started, we had already bought our popcorn.
当电影开始时，我们已经买好爆米花了。
EN： The subordinating conjunction 'when' introduces an adverbial clause of time ('When I came in') to establish the timeframe for the main event.
中文： 从属连词 'when' 引导时间状语从句（'When I came in'），用来确定主要事件发生的时间点。
EN： In Western culture, surprise parties are a very common and beloved way to celebrate birthdays. Guests typically arrive early, hide in a dark room (often behind furniture like a sofa), and jump out shouting 'Surprise!' when the guest of honor walks in.
中文： 在西方文化中，舉辦「驚喜派對」（surprise party）是慶祝生日非常流行且受歡迎的方式。賓客通常會提早到達並躲在暗處（例如沙發後面），等壽星進門時再一起跳出來大喊「Surprise!」（驚喜！）
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action or point in time in the past. In this sentence, 'had planned' happened before she 'was happy'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个时间点或动作之前已经完成的动作。在本句中，“规划（had planned）”发生在“她很高兴（was happy）”之前。
They were hungry because they had not eaten lunch.
他们那时肚子很饿，因为他们还没有吃午餐。
EN： The subordinating conjunction 'because' is used to introduce a clause that states the reason for something. It connects the main clause (the result) with the subordinate clause (the cause).
中文： 从属连词“because（因为）”用于引导表示原因的从属从句。它将主句（结果）与从属从句（原因）连接起来。
I stayed home because it was raining.
我待在家里，因为那时正在下雨。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. Here, 'had cleaned' happened before 'guests came'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前就已经完成的动作。在此句中，「打扫房间（had cleaned）」发生在「客人到来（came）」之前。
They had finished the project before the deadline passed.
在截止日期过去之前，他们就已经完成了该项目。
EN： The conjunction 'before' introduces an adverbial clause of time. In this clause, the Simple Past tense ('came') is used to establish the later reference point in the past.
中文： 连词「before」引导时间状语从句。在此从句中，使用一般过去时（came）来建立过去较晚发生的时间对照点。
I turned off the computer before I left the office.
我离开办公室之前关掉了电脑。
EN： In Western culture, hosting a surprise party requires careful coordination. Preparing the venue (cleaning, decorating) before guests arrive is a common courtesy to ensure a welcoming environment and keep the surprise hidden until the last moment.
中文： 在西方文化中，舉辦驚喜派對需要周密的協調。在客人抵達之前準備好場地（打掃、佈置）是一種常見的禮貌，以確保溫馨的氛圍，並在最後一刻前保持驚喜的神秘感。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. In this sentence, 'had decorated' happened first, followed by 'turned off' in the simple past.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前已经完成的动作。在本句中，「布置（had decorated）」先发生，随后才是简单过去时的「关灯（turned off）」。
After she had finished her homework, she went to bed.
在她写完作业之后，她就去睡觉了。
EN： The phrasal verb 'turn off' means to stop the flow of electricity, gas, or water. When the object is a noun (like 'the lights'), it can place either after 'off' or between 'turn' and 'off' (e.g., 'turned the lights off').
中文： 短语动词「turn off」表示关闭电力、煤气或水源。当宾语是名词（如「the lights」）时，可以放在「off」后面，也可以放在「turn」与「off」之间（例如「turned the lights off」）。
Please turn off the television before you leave.
请在离开前把电视关掉。
EN： The Past Perfect tense (had + past participle) is used to show that an action happened before another action in the past. In this sentence, 'had forgotten' happened before the past action 'realized'.
中文： 过去完成时（had + 过去分词）用于表示某个动作在过去的另一个动作之前已经发生。在本句中，“忘记（had forgotten）”发生在过去的动作“意识到（realized）”之前。
She realized she had left her keys in the car.
她意识到她把钥匙忘在车里了。
EN： The conjunction 'that' is often omitted in informal English when introducing a noun clause acting as the direct object of verbs like 'realize', 'think', or 'say'.
中文： 在非正式英语中，当引导名词从句作为“realize（意识到）”、“think（认为）”或“say（说）”等动词的直接宾语时，连接词“that”通常会被省略。
I think we need to buy more balloons.
我想我们需要买更多气球。
EN： In Western birthday traditions, blowing out candles on a birthday cake while making a wish is a central ritual. Forgetting the candles is a common, relatable party mishap that adds mild dramatic tension to the story.
中文： 在西方生日傳統中，在生日蛋糕上吹熄蠟燭並許願是核心儀式。忘記帶蠟燭是一個常見且能引起共鳴的派對小失誤，這為故事增添了一點戲劇性的緊張感。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. In this sentence, 'had practiced' happened before the past action 'joined'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前，就已经完成的动作。在本句中，「had practiced」（已经练习）发生在过去的另一个动作「joined」（加入）之前。
She had finished her homework before her mother came home.
在她妈妈回到家之前，她已经写完作业了。
EN： The conjunction 'before' is used to connect two clauses, indicating the chronological order of events. The clause following 'before' usually uses the Simple Past tense to mark the later event.
中文： 连词「before」（在……之前）用于连接两个从句，以表示事件发生的先后顺序。紧接在「before」后面的从句通常使用一般过去时，用来表示较晚发生的事件。
We had left the office before it started to rain.
在开始下雨之前，我们就已经离开办公室了。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before a specific point in the past. In this sentence, 'had never seen' indicates that up until the moment of the surprise party in the past, the speaker had no prior experience of seeing Leo so surprised.
中文： 过去完成时（had + 过去分词）用于描述在过去某个特定时间点之前已经完成的动作或状态。在本句中，「had never seen」表示直到过去举办惊喜派对的那一刻之前，说话者从未有过看见里奥如此惊讶的经历。
I had never tasted such a delicious cake before that day.
在那天之前，我从未尝过如此美味的蛋糕。
EN： The verb 'see' is a sensory verb that can take an object followed by an adjective (Object Complement) to describe the state of the object. Here, 'Leo' is the object, and 'so surprised' is the adjective phrase acting as the object complement, describing Leo's state.
中文： 感官动词「see」（看见）后面可以接宾语（受词）与形容词（宾语补足语），用来描述该宾语的状态。在此句中，「Leo」是宾语，「so surprised」是形容词短语作为宾语补足语，用以形容里奥当时的状态。
We found the door locked when we arrived.
我们到达时发现门是锁着的。
EN： The past perfect tense (had + past participle) is used here to describe an action that was completed before a specific point in the past. In this sentence, 'had ever thrown' refers to all the parties organized up to the moment of the party being described.
中文： 过去完成时（had + 过去分词）在此处用于描述在过去某个特定时间点之前已经完成的动作。在本句中，「had ever thrown」指的是在所描述的这场派对之前，他们举办过的所有派对。
It was the most beautiful song I had ever heard.
那是我听过最美的一首歌。
EN： The relative pronoun 'that' or 'which' is omitted in the adjective clause 'we had ever thrown' because it functions as the direct object of the verb 'thrown'. This omission is very common in informal and spoken English.
中文： 在定语从句「we had ever thrown」中，关系代词「that」或「which」被省略了，因为它在从句中充当动词「thrown」的宾语。这种省略在口语和非正式英语中非常常见。
This is the book I bought yesterday.
这是我昨天买的那本书。
EN： In English, the idiom 'to throw a party' is a very common and informal way to say 'to organize or host a party'. Using 'make a party' is a common mistake for non-native speakers.
中文： 在英文中，片語「to throw a party」是表達「舉辦派對」非常道地且常用的非正式說法。非母語人士常會誤用「make a party」，應特別注意避免。
EN： The phrase 'throw a party' is a common English idiom meaning to host or organize a party. It is more informal and natural in spoken English than 'host a party' or 'organize a party'.
中文： 短语“throw a party”是英语中常见的惯用语，意思是举办或组织一场派对。在英语口语中，它比“host a party”或“organize a party”更非正式且更自然。
We are planning to throw a party for Sarah's graduation next month.
我们计划下个月为莎拉的毕业典礼举办一场派对。
EN： The Simple Past Tense ('threw') is used to describe an action that was completed at a specific time in the past, which is indicated here by the time marker 'Last week'.
中文： 一般过去时（此处为“threw”）用于描述在过去特定时间完成的动作，在此处由时间标记“Last week”（上周）指出。
Last year they traveled to Japan for their honeymoon.
去年他们去日本度了蜜月。
EN： In Western culture, 'surprise parties' are a very popular way to celebrate milestones or birthdays. Co-workers, friends, or family members secretly plan the event, and the guest of honor is kept completely in the dark until they arrive at the venue and everyone yells 'Surprise!'
中文： 在西方文化中，「驚喜派對」（surprise parties）是慶祝里程碑或生日非常流行的方式。同事、朋友或家人會秘密策劃活動，而主角在到達現場、大家大喊「Surprise!」（驚喜！）之前，對此完全不知情。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before another action or a specific time in the past.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。
They had already left when we arrived at the station.
当我们到达车站时，他们已经离开了。
EN： The phrase 'before the big day' uses 'before' as a preposition followed by a noun phrase to indicate a time prior to a major, highly anticipated event (often a wedding, a big party, or an exam).
中文： 介词「before」后面接名词短语「the big day」（大日子/重要日子），用来表示在某个备受期待的重要事件（如婚礼、大型派对或考试）之前的时间点。
She felt very nervous the night before the big day.
在大日子的前一天晚上，她感到非常紧张。
EN： The idiom 'the big day' is a common informal English expression used to refer to a very important, scheduled event in someone's life, most commonly a wedding day, but it can also refer to a major party, graduation, or the launch of a significant project.
中文： 英文成語「the big day」是一個非常常見的非正式表達，用來指代某人生命中非常重要且已排定的日子。最常見的是指「婚禮當天」，但也可以用來指重大的派對、畢業典禮或重要項目的發表日。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. Here, 'had hidden' happened before the past action 'arrived'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前就已经完成的动作。在此句中，「藏礼物（had hidden）」发生在另一个过去动作「到达（arrived）」之前。
By the time the movie started, we had already bought our popcorn.
在电影开始之前，我们就已经买好爆米花了。
EN： 'By the time' is a subordinating conjunction used to introduce a time clause, meaning 'no later than the moment that'. It is commonly paired with the past perfect in the main clause.
中文： 「By the time」是一个从属连词，用来引导时间状语从句，意思是「到了…的时候」或「在…之前」。主句通常搭配过去完成时来强调动作的先后顺序。
By the time she called me, I had fallen asleep.
在她打给我之前，我早就睡着了。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before another action or a specific time in the past.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。
She had already left when I arrived at the station.
当我到达车站时，她已经离开了。
EN： The temporal phrase 'the night before' is commonly used with the past perfect tense to refer to the night preceding a specific past event, rather than 'last night' which is used relative to the present.
中文： 时间副词短语「the night before」（前一天晚上）常用于过去完成时，指代过去某个特定事件的前一晚，而非相对于现在的「last night」（昨天晚上）。
He realized he had lost the keys he bought the night before.
他意识到他弄丢了前一天晚上买的钥匙。
EN： In Western party planning, baking a cake from scratch the night before is a common tradition, showing care and preparation for the guest of honor. Using 'the night before' instead of 'yesterday' is essential when narrating a story set entirely in the past.
中文： 在西方派對文化中，在前一天晚上親手製作蛋糕是一項常見的傳統，展現對壽星的用心與準備。在敘述一個完全發生在過去的故事時，使用「the night before」而非「yesterday」是符合英文敘事習慣的表達方式。
EN： The Past Perfect tense (had + past participle) is used to describe an action that was completed before another action or a specific time in the past. In this sentence, 'had blown up' and '[had] hung' indicate actions completed before the party started.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。在本句中，「had blown up」（已经吹好）和「[had] hung」（已经挂上）表示在派对开始前就已完成的动作。
By the time the guests arrived, we had already cleaned the house.
在客人到达之前，我们就把房子打扫干净了。
EN： Parallel structure with coordinate conjunctions. When connecting two past perfect verbs with 'and', the auxiliary verb 'had' can be omitted in the second clause to avoid repetition (had blown up... and [had] hung...).
中文： 并列连词的平行结构。当使用「and」连接两个过去完成时的动词时，第二个从句中的助动词「had」可以省略以避免重复（had blown up... and [had] hung...）。
She had finished her homework and watched a movie before dinner.
她在晚餐前就已经写完作业并看了一部电影。
EN： In Western culture, surprise parties are a popular way to celebrate milestones or birthdays. Preparing the venue with balloons and 'bright lights' (often fairy lights or string lights) is a classic way to create a festive and warm atmosphere before the guest of honor arrives.
中文： 在西方文化中，驚喜派對（surprise party）是慶祝重要日子或生日的流行方式。在主角到達之前，用氣球和「明亮的燈飾」（通常指裝飾燈串或彩燈）來佈置場地，是營造節日和溫馨氣氛的經典做法。
EN： The Past Perfect Tense ('had' + past participle) is used to describe an action that was completed before another action or a specific time in the past.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前，就已经完成的动作。
They had already left when we arrived at the station.
当我们到达车站时，他们已经离开了。
EN： The adverbial phrase 'many times before' is used to indicate frequency and prior experience relative to a past reference point.
中文： 副词短语「many times before」（在这之前很多次）用于表示相对于过去某个时间点的频率和先前的经历。
I had visited that museum many times before it closed.
在那家博物馆关闭之前，我已经去过很多次了。
EN： In Western culture, surprise birthday parties require meticulous planning and secrecy. Practicing songs or hiding gifts beforehand is a common collective effort among friends to show deep affection and create a memorable experience for the birthday person.
中文： 在西方文化中，驚喜生日派對需要極其周密的計畫與保密。事先練習歌曲或隱藏禮物是朋友們常見的集體合作方式，旨在表達深厚的友情並為壽星創造難忘的回憶。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. In this sentence, 'had already turned off' happened before 'opened'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前就已经完成的动作。在本句中，“已经关灯（had already turned off）”发生在“开门（opened）”之前。
When the movie started, we had already bought our popcorn.
当电影开始时，我们已经买好了爆米花。
EN： Adverbial clauses of time introduced by 'when' establish the temporal relationship between two past events. The event in the 'when' clause is in the simple past, while the main clause uses the past perfect to emphasize completion.
中文： 由“when”引导的时间状语从句用来建立两个过去事件的时间关系。在“when”从句中的事件使用一般过去时，而主句则使用过去完成时以强调其先行完成性。
When Sarah arrived at the station, the train had left.
当莎拉到车站时，火车已经开走了。
EN： In Western culture, surprise parties are a popular way to celebrate milestones or birthdays. Guests typically arrive early, hide in a darkened room, and yell 'Surprise!' when the host turns on the lights or when the guest of honor walks in. Turning off the lights is a crucial step to make the room appear empty.
中文： 在西方文化中，驚喜派對（surprise party）是慶祝生日或重要里程碑的流行方式。賓客通常會提早到達，躲在黑暗的房間裡，並在主角進門或開燈時大喊「Surprise!」（驚喜！）。關掉電燈是讓房間看起來空無一人的關鍵步驟。
EN： The phrase 'have no idea' is a common idiomatic expression meaning 'to not know at all'. It is often followed by a noun clause introduced by 'that' or a wh-question word (e.g., 'what', 'where', 'who') to specify what the person does not know.
中文： 短语“have no idea”是一个常见的惯用语，意思是“完全不知道”。后面通常会接由“that”引导的名词从句，或是疑问词（如 what、where、who）引导的从句，用来具体说明不知道的事情。
I had no idea that you were waiting for me.
我完全不知道你那时的等我。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before another action or a specific time in the past. In this sentence, 'had prepared' happened before the state of him having 'no idea' (which is in the simple past).
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。在本句中，“had prepared”（已经准备）发生在“had no idea”（不知道，为一般过去时）之前。
By the time the movie started, we had already bought our popcorn.
在电影开始之前，我们就已经买好爆米花了。
EN： The past perfect tense ('had + past participle') is used here within a relative clause to describe an action that was completed before a specific point in the past (the party itself). When paired with a superlative adjective like 'the happiest', it emphasizes life experience up to that past moment.
中文： 过去完成时（had + 过去分词）在此处用于定语从句中，表示在过去某个特定时间点（即派对举办时）之前已经完成的动作或经历。当与最高级形容词（如 the happiest）连用时，用以强调截至该过去时间点为止的人生经历。
It was the most beautiful place I had ever visited.
那是我去过的最美丽的地方。
EN： The relative pronoun 'that' or 'which' is omitted in this sentence because it functions as the direct object of the verb 'made' in the defining relative clause 'we had ever made together'.
中文： 在本句中，关系代词（that 或 which）被省略了，因为它在限定性定语从句「we had ever made together」中充当动词「made」的宾语。
This is the book (that) I bought yesterday.
这是我昨天买的那本书。
EN： In English, 'to make a party' or 'to throw a party' are common collocations, with 'throw' being more informal and frequent. Using 'make' here emphasizes the collective effort of planning and creating the event together.
中文： 在英文中，「舉辦派對」常用 throw a party 或 hold a party。此處使用 make a party 帶有「共同創造、打造」這場派對的意味，強調大家齊心協力準備的過程。
EN： Past Perfect Tense (Had + Past Participle) is used to describe an action that was completed before another action or a specific time in the past. In questions, the auxiliary verb 'had' is placed before the subject.
中文： 过去完成时（Had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。在疑问句中，助动词「had」要放在主语之前。
Had you finished the report before the meeting started?
会议开始前你已经写完报告了吗？
EN： The preposition 'before' is used to indicate that an event happened prior to a specific time, event, or action (in this case, 'lunch').
中文： 介词「before」用于表示某个事件发生在特定时间、事件或动作（在此句中为「午餐」）之前。
We arrived at the theater before seven o'clock.
我们在七点前就到了剧院。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before a specific point in time or another action in the past.
中文： 过去完成时（had + 过去分词）用于描述在过去某个特定时间点或另一个过去动作之前就已经完成的动作。
By the time the guests arrived, I had cleaned the living room.
在客人到达之前，我已经打扫好了客厅。
EN： The preposition 'before' is used to indicate that an event happened prior to a specific time (in this case, 'noon').
中文： 介词「before」（在……之前）用于表示某个事件发生在特定时间点（在此处为「noon」中午）之前。
Please submit the report before Friday.
请在星期五之前提交报告。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. In this sentence, 'had cleaned' happened before the guests 'came'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个时间点或动作之前，已经完成的动作。在此句中，“打扫房间”（had cleaned）发生在“客人来”（came）之前。
They had finished the project before the deadline passed.
在截止日期过去之前，他们就已经完成了这个项目。
EN： The conjunction 'before' is used to connect two clauses, indicating the chronological order of events. The clause following 'before' usually uses the Simple Past tense when referring to past events.
中文： 连词“before”（在……之前）用于连接两个从句，以指示事件的时间顺序。在描述过去的事件时，“before”引导的从句通常使用一般过去时。
She turned off the computer before she left the office.
她在离开办公室之前关掉了电脑。
EN： The Past Perfect Tense (had + past participle) is used to describe an action that was completed before another action in the past. In questions, the auxiliary verb 'had' is placed before the subject.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或时间点之前就已经完成的动作。在疑问句中，助动词「had」要放在主语之前。
Had you finished the report before the meeting started?
在会议开始之前，你已经完成报告了吗？
EN： The conjunction 'before' introduces an adverbial clause of time. When referring to past events, the verb in the 'before' clause is typically in the Simple Past Tense to show it happened after the Past Perfect action.
中文： 连词「before」（在……之前）引导时间状语从句。当描述过去的事件时，「before」从句中的动词通常使用一般过去时，以表示该动作发生在过去完成时动作之后。
They had left the office before it began to rain.
在开始下雨之前，他们就已经离开办公室了。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before a specific point in the past. In this sentence, 'had never imagined' indicates that the speaker's lack of imagination occurred prior to the moment of receiving the surprise.
中文： 过去完成时（had + 过去分词）用于描述在过去某个特定时间点之前已经完成的动作或状态。在本句中，“had never imagined”（从未想象过）表示说话者在收到惊喜之前的过去时间里，一直没有料想到这件事。
I had never seen such a beautiful sunset before I visited Greece.
在我去希腊旅游之前，我从未见过如此美丽的日落。
EN： The determiner 'such' is used before a noun phrase (here, 'a surprise') to add emphasis, meaning 'of this kind' or 'so great'.
中文： 限定词“such”用于名词短语（此处为“a surprise”）之前以示强调，表示“如此的”或“这样的”。
It was such a lovely day that we decided to have a picnic.
那是如此美好的一天，以至于我们决定去野餐。
EN： In Western culture, surprise parties are a very common and cherished way to celebrate milestones or birthdays. The expression of overwhelming surprise and gratitude, as shown in Leo's reaction, is a typical and polite response to such friendly gestures.
中文： 在西方文化中，舉辦驚喜派對（surprise party）是一種非常普遍且受歡迎的慶祝生日或里程碑的方式。里奧所表現出極度驚訝與感激的反應，是對朋友們善意舉動的典型且禮貌的回應。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. The later action is expressed in the Simple Past tense.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前，已经完成的动作。而较晚发生的动作则使用一般过去时表示。
By the time the train arrived, we had bought our tickets.
在火车到达之前，我们就已经买好车票了。
EN： 'By the time' is a subordinating conjunction used to introduce a time clause, meaning 'no later than the moment that'. It often triggers the use of the perfect aspect in the main clause.
中文： 「By the time」是一个从属连词，用来引导时间状语从句，意思是「不迟于…的时候」或「在…之前」。它通常会使主句中使用完成时。
EN： The Past Perfect Tense ('had' + past participle) is used to show that an action was completed before another action in the past. In this sentence, 'had left' happened before the action of realizing ('realized').
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前已经完成的动作。在本句中，「把礼物忘在家里」（had left）发生在「意识到」（realized）这个过去动作之前。
She realized she had lost her keys.
她意识到她把钥匙弄丢了。
EN： The conjunction 'that' is often omitted in informal English when introducing a noun clause functioning as the direct object of verbs like 'realize', 'think', or 'know'. Here, 'I had left...' is a noun clause acting as the object of 'realized'.
中文： 在非正式英语中，引导名词从句作为“realize（意识到）”、“think（认为）”或“know（知道）”等动词的直接宾语时，连接词“that”经常会被省略。在此处，“I had left...”是作为“realized”宾语的名词从句。
I think we have met before.
我想我们以前见过面。
EN： The Past Perfect tense ('had' + past participle) is used to describe an action that was completed before another action or a specific time in the past. In this sentence, 'had bought' happened before the speaker realized they forgot the gifts.
中文： 过去完成时（had + 过去分词）用于描述在过去某个动作或特定时间点之前就已经完成的动作。在本句中，「had bought」（已经买了）发生在说话者意识到自己忘记带礼物之前。
By the time the movie started, we had already bought our popcorn.
在电影开始之前，我们就已经买好爆米花了。
EN： The pronoun 'one' is used as a substitute to avoid repeating a singular countable noun that has already been mentioned or is clear from the context (in this case, 'a gift').
中文： 代词「one」用来替代前面已提过或从上下文中显而易见的单数可数名词，以避免重复（在此处指「礼物」）。
I lost my pen, so I need to buy a new one.
我的笔掉了，所以我需要买一支新的。
EN： The Past Perfect tense ('had' + past participle) is used to show that an action was completed before another action in the past. In this sentence, 'had sung' happened before 'shared'.
中文： 过去完成时（had + 过去分词）用于表示在过去某个动作或时间点之前已经完成的动作。在本句中，「唱歌（had sung）」发生在「分享（shared）」之前。
After she had finished her homework, she watched TV.
在她写完作业之后，她看了电视。
EN： The subordinating conjunction 'after' is used to introduce a dependent clause that indicates the sequence of events, showing that the action in the 'after' clause occurred first.
中文： 从属连词「after（在……之后）」用于引导从属从句，用以表示事件的先后顺序，说明「after」从句中的动作是先发生的。
After we had eaten dinner, we went for a walk.
在我们吃完晚餐之后，我们去散步了。
EN： In Western birthday celebrations, singing the 'Happy Birthday' song is a key ritual that always precedes the blowing out of candles and the cutting/sharing of the cake. This sentence reflects that specific chronological sequence of party traditions.
中文： 在西方生日慶祝活動中，唱「生日快樂歌」是一個關鍵儀式，通常在吹熄蠟燭和切分蛋糕之前進行。這句話反映了派對傳統中特定的時間先後順序。
EN： The use of 'what' as a nominal relative pronoun (also called a fused relative pronoun). It functions as 'the thing(s) that' and introduces a noun clause that acts as the direct object of the verb 'forget'.
中文： 「what」作为关系代词的用法（又称融合关系代词），相当于「the thing(s) that」（所……的事物），引导一个名词性从句，在此句中作为动词「forget」的宾语。
I don't understand what you are trying to say.
我不懂你想要表达的意思。
EN： The Past Perfect tense ('had done') is used here to emphasize that the action of 'doing' occurred and was completed prior to a specific point in the past or before the speaker's current state of gratitude.
中文： 过去完成时（had + 过去分词）在此处用于强调「付出、帮忙」的动作，是在过去某个特定时间点或说话者产生感激之情之前，就已经发生并完成的事实。
She appreciated what they had prepared for her.
她很感激他们为她所做的一切。
EN： In English-speaking cultures, expressing deep, sincere gratitude is highly valued, especially after a major effort or surprise organized by friends. Using the past perfect ('had done') emphasizes the lasting impact of their past actions on the speaker's present feelings.
中文： 在英語系國家中，真誠地表達深切謝意是非常重要的社交禮儀，特別是在朋友為自己精心準備了驚喜或付出巨大努力之後。使用過去完成式（had done）能更深刻地強調對方過去的付出對說話者現在及未來所產生的深遠影響。
重要单词附有 IPA 发音、定义、例句和互动式测验。
在本文中： 到达、抵达某处
在本文中： 躲藏、隐藏（hide 的过去分词）
在本文中： 计划、策划
在本文中： 装饰、布置
在本文中： 意识到、明白
在本文中： 练习、排练
在本文中： 感到惊讶的、出人意料的
在本文中： 准备、筹备
在本文中： 猜测、料想到
在本文中： 想象、设想
在本文中： 备用的、多余的
片语包含类型标示、双语定义、用法说明和例句。
Used to specify a limit of time by which something has happened or will happen.
到……的时候
To inflate something, such as a balloon, with air or gas.
充气、充大（如气球）
To stop the operation or flow of something (like a light or machine) by pressing a button or moving a switch.
关掉（电源、灯火、电器等）
To host or organize a social gathering or celebration.
举办派对
To not know something at all; to be completely unaware of something.
完全不知道、毫无头绪