As Calvin said "precise" is unnecessary and/or not a good word to use here. There are other adjectives you perhaps meant to use? - Comprehensive - explained it really well. - Thorough - explained it really well. - Thoughtful - considerate and well thought out. - Helpful - it really helped me. Otherwise it is fine: Had it not been for your helpful response, I would have continued using that idiom without knowing about / realising / understanding the sexual connotations! It is slightly formal, as Kayla said, but not an unusual way of writing. I would write like this if I was being polite to someone I didn't know. You could also say: - Thanks for letting me know about that idiom. I didn't realise it meant that!

It's grammatically correct, but it sounds awkward and formal. I think that, "thanks for letting me know! I'm so glad I didn't say that to anyone 😅" or " I'm so glad you stopped me before I said that to someone lol" or the like should do. I'm assuming you're saying this to someone on italki?

You do not need "precise". You can also use "response" instead of "reply". Otherwise, it sounds pretty good.