In the following sentence, is it correct grammar to capitalize the first word after dialogue is written?. Here's an example. "Oh?" T(?)he therapist responded in surprise. "And what was that" S(?)he asked. If anyone could clarify this I'd greatly appreciate it, thanks!
Don't capitalize. The dialogue tag is technically part of the sentence. You can verify this by reading any novel, you know - go ahead and pick up a book!
I thought the dialogue ending in question mark (?) or exclamation (!) should have tags starting with capital letters, otherwise you should have a comma at the end of the dialogue inside the quotation marks and the tags should start with small letters. I don't have time to verify, so I may be wrong.
No, don't capitalise if it's an 'extra bit' of what she's saying e.g. '"Why are you doing that?" she asked (no capital letter needed).' However, if it's NOT something like this, then it does need to be capitalised e.g. '"Are you all right?" He grinned (there needs to be a capital letter here because you can't say a grin).' Hope that helps.