Still confused about putting 了 at the end of a sentence or right after the verb Obviously this question is very similar to When should 了 be after the verb and when should it be at the end of the sentence?. I just wanted you to know that I consulted that before I posted this question.

I'm working through Rosetta Stone and I have a screenshot that illustrates what I'm struggling with.


So here we have two instances where le is appearing at the end of the sentence and one where it appears immediately after the verb. However, all three sentences involve someone giving an item to someone else so I would think they would all follow the same grammar rules. Here is another example:



In both pictures someone finished eating something so I would think they would follow the same grammar. So why does le appear after the verb in one picture but at the end of the sentence in the other?
The order where 了 appears in the sentence is important: when placed at the end of a sentence, it represents a change of state (it has nothing to do with tenses); when placed at the end of a verb, it represents a completed action. Using the examples in your question:


他们给我写信了 They wrote me a letter. (This is the first time I receive
a letter from them.)
他们给我写了信 They have written me a letter. (This is the fifth letter
from them.)
她给我们买巧克力了 She bought us chocolate. (It has been a long while since she last treated us.)
她给我们买了巧克力 She just bought us chocolate. (Oh, she bought some yesterday too.)