Please, what is the difference between 我吃了反了 and 我吃饭了？
I find it in a lot of sentences, for example 我买了衬衫了 instead of 我买衬衫了
我吃了饭=>了here is an auxiliary indicating a perfective aspec. When this is said, something else is expected to follow.
我吃饭了 ==> 了 here is a modal particle expressing an affirmative mood. It can be used at the end of what the speaker has got to say.
I hope you can understand:)
Thank you :)