I am learning English. yesterday i said to my friend "please remind me that this evening" then he told me this sentence is wrong. i have searched it but i did not find any mistake in this sentence. please identify mistake and explain it. thanks.
The sentence is understandable, but there are several things that could be done so it wouldn't be called "wrong."
The most likely is to add a preposition before that:
Please remind me of that this evening.
Please remind me about that that this evening.
But there are also other things you could do to make it more natural.
You could remove that altogether:
Please remind me this evening.
You could replace that with a reference to something:
Please remind me about the assignment this evening.
Please remind me to make that call this evening.
You could remove that and add the reference at the end of the sentence:
Please remind me this evening about the assignment.
Please remind me this evening to make that call.
You could add a reference after that:
Please remind me that it's due this evening.
Please remind me that I have a dinner date this evening.
Note that this form is somewhat ambiguous. Normally, it's taken to mean that you want to be reminded in the evening about those things.
However, it could be taken to mean that you want to be reminded right now that something is happening in the evening. This is not a normal interpretation, but some people will deliberately make that interpretation in order to turn it into a joke:
"Please remind me that it's due this evening."
"It's due this evening."
"Very funny . . ."