Le 了 is used after action verbs in the past t - Cchatty

Le 了 is used after action verbs in the past tense Only with a simple verb object compound, such as kànshū 看书 or chīfàn 吃饭, can you put a le 了either after the verb or after the direct
object:

She read a book.
Tā kàn le shū. OR Tā kánshū le.
她看了书。OR 她看书了。

She ate (a meal).
Tā chīle fàn. OR Tā chīfàn le.
她吃了饭。OR 她吃饭了。

BUT, if you put the le 了 right after the verb and before the direct object, it implies someone has just done something in the immediate past (“has/have just read a book”; “has/have just eaten a meal”). If you put the le了 after the direct object, it implies someone did something in the not so immediate past (“read a book or did read a book”; “ate a meal or did eat a meal”).

There are two simple verb-object compounds, however, where the le 了 tends to always come after the direct object, namely shuìjiào 睡觉 and sànbù 散步. These are verbs that
tend to only take one particular direct object. You can eat (吃) many different things and you can read/look at (看) various things, but sleep 睡 can only take 觉 as a direct
object, for example:

She fell asleep./She slept.
Tā shuìjiào le.
她睡觉了。

If the direct object is not a simple generic one, like fàn 饭 or shū 书, but more specific and therefore longer, such as Zhōngguó fàn 中国饭 or hěn duō Zhōngwén shū 很多中文书,
then le了 always comes right after the verb and before the direct object, regardless of when in the past it occurred.

I ate Chinese food.
Wǒ chī le Zhōngguó fàn.
我吃了中国饭。

My friend read a lot of Chinese books.
Wǒde péngyou kàn le hěn duō Zhōngwén shū.
我的朋友看了很多中文书。

However, if there is a sequence of action verbs, where you want to say that after doing one thing, someone did something else, then the le 了directly follows the first action verb but for the final verb in the sequence the le 了 comes after the direct object and at the end of the
sentence.

After eating (having eaten) dinner, I fell asleep.
Wǒ chīle wǎnfàn jiù shuìjiào le.
我吃了晚饭就睡觉了。

If it’s a sequence of events in the present or future tense, where you’re saying that having done one thing someone does or will do another, then the le 了 comes after the first verb in the sequence and there is no le了 at the end of the sentence.

After eating (having eaten dinner, I study.
Wǒ chīle wǎnfàn jiù niànshū .
我吃了晚饭就念书。

After eating (having eaten) dinner, I’ll go see a movie.
Wǒ chīle wǎnfàn jiù huì qù kàn diànyǐng.
我吃了晚饭就会去看电影。

If you list a number of things you did, then the le 了comes after the action verb and before the direct object for every verb except the last one, for which the le 了 comes at the end, after the direct object.

Yesterday I ate dinner, studied, watched TV, and then went to sleep.
Wǒ zuótiān chīle wǎnfàn, niànle shū, kànle diànshì jiù shuìjiào le.
我昨天吃了晚饭，念了书，看了电视就睡觉了。

WHEN le 了 is placed BOTH after the verb AND at the end of the sentence, then the implication is that the action occurred in the past and is still going on.

He has read two books (and is still continuing to read).
Tā kàn le liǎngběn shū le.
他看了两本书了。

I have studied Chinese for two years (and am still studying it).
Wǒ xuéle liángnián de Zhōngwén le.
我学了两年的中文了。

NOTE the difference between “did” something and “have done” something, le 了 vs. guò 过:

Last year she went to China.
Tā qùnián qùle Zhōngguó.
她去年去了中国。

BUT:
She’s been to China, so she has eaten real Chinese food.
Tā qùguò Zhōngguó , suǒyǐ tā chīguò zhēnzhèngde Zhōngguó cài.
她去过中国，所以她吃过真正的中国菜。