Sometimes, we say more than a sentence or we have a really long idea. This is a good way to ask if what you said at the moment was grammatically correct. I hope that this helps. :)
The first sentence is one of the most common and simplest ways to ask the question. This lets the person know that you want to make sure that all grammar was used correctly in your sentence. In sentence two, you can simply ask if you made any mistakes, and the person will understand that you are referring to grammar. In the third sentence, you can use the word 'errors' to mean the same as 'mistakes'.
"Would you please be able to tell me whether or not that was grammatically correct?"
If you would like to know whether or not the sentence you just said was grammatically correct or not, you could ask "Was my sentence grammatically correct?" or "Would you please be able to tell me whether or not that was grammatically correct?". Both these sentences illustrate your desire, to find out whether what you said in English was grammatically correct or not.
直前言った文が文法的に正しかったかどうか確認したいなら、次のように言えます。
"Was my sentence grammatically correct?"（私の文は文法的に正しかったですか）
"Would you please be able to tell me whether or not that was grammatically correct?".（文法的には正しかったでしょうか）
どちらの文を使っても、言ったことが文法的に正しかったかどうか確認したいことが伝わります。
When you want to check with someone whether what you just said was grammatically correct, then you may ask in the following ways:
-Was my sentence grammatically correct?
-Was my grammar okay?
直前に言ったことが文法的に正しかったかどうか相手に確認したいなら、次のように言えます。
-Was my sentence grammatically correct?（私の文は文法的に正しかったですか）
-Was my grammar okay?（文法は大丈夫でしたか）
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