Lie and lay describe two different actions: lie is about a subject resting or being in a position, while lay is about putting something somewhere. The key difference is whether there is a direct object that receives the action. Lie is usually intransitive, and lay is usually transitive. Mastering them depends on matching the meaning first, then choosing the correct verb form.

Use lie when the subject rests, reclines, or is located somewhere, and no direct object is acted on. You can often replace lie with be resting or be located. Lie answers the question “What is the subject doing” rather than “What is the subject doing to something.” Common contexts include people, animals, and objects in a resting position.

Rule	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Use lie for resting or reclining with no object	📌 对于没有对象的休息或躺卧，请使用 lie	I lie on the couch after work.	🗣️ 我在下班后躺在沙发上。
Use lie for location when something is situated somewhere	📌 当某物位于某处时使用 lie	The keys lie on the table.	🗣️ 钥匙躺在桌子上。
If you can add a thing being placed, you likely need lay instead	📌 如果你能加上被放置的东西，通常应使用 lay	I lie down, but I lay the book down.	🗣️ 我躺下，但我把书放下。

Use lay when the subject places something else onto a surface or into a position. Lay takes a direct object, the thing being put somewhere. You can often replace lay with put or place. If you can answer “Lay what,” you are using lay correctly.

Rule	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Use lay when you put an object somewhere	📌 当你把物体放在某处时使用 lay	Please lay the jacket on the chair.	🗣️ 请把外套放在椅子上。
Lay must have a direct object stated or clearly understood	📌 lay 必须有一个明确陈述或清楚理解的直接宾语	Lay your phone face down.	🗣️ 把你的手机正面朝下放好。
If put works, lay usually works	📌 如果 put 可行，lay 通常也可行	I put my bag down → I lay my bag down.	🗣️ I put my bag down → I lay my bag down.

Lie changes form in a way many learners find confusing because the past tense is lay. The present is lie, the past is lay, and the past participle is lain. Use the past participle with have or had. These forms all keep the intransitive meaning of resting or being located.

Subject	🇨🇳 中文 主语	Form	🇨🇳 中文 形式	Example	🇨🇳 中文 示例
I	👤 I	lie	🔤 lie	I lie down early.	🗣️ 我很早就躺下。
you	👤 you	lie	🔤 lie	You lie on the grass.	🗣️ 你躺在草地上。
he	👤 he	lies	🔤 lies	He lies awake at night.	🗣️ 他夜里醒着躺着。
she	👤 she	lies	🔤 lies	She lies on the sofa.	🗣️ 她躺在沙发上。
it	👤 it	lies	🔤 lies	It lies under the bed.	🗣️ 它躺在床下。
we	👥 we	lie	🔤 lie	We lie in the sun.	🗣️ 我们在阳光下躺着。
you	👥 you	lie	🔤 lie	You lie down for a minute.	🗣️ 你躺下休息一分钟。
they	👥 they	lie	🔤 lie	They lie on the sand.	🗣️ 他们躺在沙滩上。

Lay has a regular-looking past tense and past participle: laid and laid. The base form is lay, and it normally requires a direct object. Use laid with have or had. These forms keep the transitive meaning of placing something.

Subject	🇨🇳 中文 主语	Form	🇨🇳 中文 形式	Example	🇨🇳 中文 示例
I	👤 I	lay	🔤 lay	I lay the papers on the desk.	🗣️ 我把 papers 放在桌子上。
you	👤 you	lay	🔤 lay	You lay the baby in the crib.	🗣️ 你把婴儿放在婴儿床里。
he	👤 he	lays	🔤 lays	He lays the towel on the chair.	🗣️ 他把毛巾放在椅子上。
she	👤 she	lays	🔤 lays	She lays the book on the shelf.	🗣️ 她把书放在书架上。
it	👤 it	lays	🔤 lays	It lays eggs in spring.	🗣️ 它在春天下蛋。
we	👥 we	lay	🔤 lay	We lay the cards on the table.	🗣️ 我们把牌放在桌子上。
you	👥 you	lay	🔤 lay	You lay the tools in the box.	🗣️ 你们把工具放在箱子里。
they	👥 they	lay	🔤 lay	They lay blankets on the ground.	🗣️ 他们把毯子放在地上。

The main trap is that lay appears in both verb families: it is the base form of lay, but it is also the past tense of lie. To decide, check meaning and object first. If it means was resting or was located, lay is past of lie and takes no object. If it means placed something, lay is present and should have an object, or laid is past of lay.

Rule	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Past of lie is lay with no object	📌 lie 的过去式是 lay，且无对象	Yesterday I lay on the beach.	🗣️ 昨天我躺在海滩上。
Past of lay is laid with an object	📌 lay 的过去式是 laid，且有对象	Yesterday I laid the towels out.	🗣️ 昨天我把毛巾摊开。
Past participle of lie is lain with have or had	📌 lie 的过去分词是 lain，与 have 或 had 搭配	She has lain there for hours.	🗣️ 她已经在那里躺了好几个小时。
Past participle of lay is laid with have or had	📌 lay 的过去分词是 laid，与 have 或 had 搭配	We have laid new flooring.	🗣️ 我们铺好了新的地板。

Lain is the past participle of lie and is mainly used with perfect tenses and a few formal set phrases. It does not take a direct object because it belongs to lie. In everyday speech, people sometimes avoid lain and rephrase, but lain is correct and common in writing. Use it when emphasizing duration or completed time up to now.

Rule	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Use has or have with lain to show time up to now	📌 用 has 或 have 搭配 lain 表示至今的时间	They have lain in wait all morning.	🗣️ 他们整上午都在埋伏等待。
Use had lain for a past time before another past event	📌 在另一个过去事件之前的过去时间里使用 had lain	The book had lain untouched for months.	🗣️ 那本书好几个月没有翻动过。
Lain keeps the meaning of resting or being located	📌 lain 保持“休息或位于”的含义	The town has lain in ruins since the war.	🗣️ 自战争以来，这座城镇一直处于废墟之中。

When choosing between lie and lay, use a quick meaning-and-object test. First ask whether something is being placed. If yes, use lay or laid. If not, and the subject is resting or located, use lie, lay, or lain depending on tense. This approach avoids memorizing forms without understanding.

Rule	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
If you can answer “What did you put,” use lay	📌 如果你能回答“你放了什么”，使用 lay	I lay the keys on the counter.	🗣️ 我把钥匙放在柜台上。
If you cannot supply a direct object, use lie	📌 如果你不能给出直接宾语，使用 lie	I lie down for a nap.	🗣️ 我躺下睡一会儿。
If it happened yesterday and means resting, use lay	📌 如果它发生在昨天并且意味着在休息，使用 lay	I lay there quietly.	🗣️ 我在那里安静地躺着。
If it uses have or had and means resting, use lain	📌 如果它使用 have 或 had 并且意味着休息，使用 lain	I have lain awake all night.	🗣️ 我整夜都醒着躺着。

A few common phrases preserve older or fixed uses and can help you recognize correct forms in context. Some are formal, but they appear often in writing and news. These expressions still follow the lie versus lay meaning difference. Learning them as chunks can reduce hesitation.

Word/Phrase	🇨🇳 中文 单词/短语	Definition	🇨🇳 中文 定义	Example	🇨🇳 中文 示例
lie down	🧩 lie down	recline or rest	🧩 斜靠或休息	I need to lie down.	🗣️ 我需要躺下。
lie ahead	🧩 lie ahead	be in the future	🧩 将来在前方	Difficult days lie ahead.	🗣️ 将来会有艰难的日子。
lie awake	🧩 lie awake	stay awake while resting in bed	🧩 睡眠中保持清醒	He lies awake worrying.	🗣️ 他醒着担忧。
lay the table	🧩 lay the table	set plates and utensils for a meal	🧩 为用餐摆放餐具	She laid the table for dinner.	🗣️ 她为晚餐摆好了桌子。
lay down the law	🧩 lay down the law	state rules firmly	🧩 坚定地规定规则	The coach laid down the law.	🗣️ 教练定下了规矩。
lie in wait	🧩 lie in wait	hide and wait to act	🧩 藏身等待行动	They had lain in wait nearby.	🗣️ 他们在附近埋伏等待。

Lie also means to say something untrue on purpose. This is a different verb from lie meaning recline, but it shares the same present form, which can confuse learners. Its past tense is lied and its past participle is lied. Context usually makes the meaning clear because it involves speech or honesty rather than position.

Rule	🇨🇳 中文 规则	Example	🇨🇳 中文 示例
Lie meaning speak falsely uses lied in the past	📌 lie 涉及说谎，过去时用 lied	He lied about his age.	🗣️ He lied about his age。
This lie does not use lain	📌 这个 lie 不使用 lain	She has lied before.	🗣️ She has lied before。
If the meaning is honesty, choose lied not lay	📌 如果含义是诚实，选 lied 而不是 lay	I lied, but I lay down afterward.	🗣️ I lied, but I lay down afterward。