Thank you native English speakers in advance , (then) I raise my queries about really two sort of questions. I don't worry , you can help me at your leisure. 1a. What John did to his suit was to ruin it. 2a. What John did to his suit was ruin his suit. 3a. What John did was to ruin his suit. Question : Which is grammatically correct? Do they have the same meaning? From 1a. , 2a., 3a., (they all belong to the “ what- type cleft sentence” ), strictly by grammar, I guess they are respectively changed into 1b., 2b., 3b. (normal sentence) as follows: 1b. John ruined his suit to it . I guess: Though the “to it (=to his suit) is very wordy in this sentence, but “to it” never causes any misunderstanding or ambiguity) 2b. John ruined his suit to his suit. (the same way to analyze as in 1b) 3b. John ruined his suit. Question : Which is grammatically correct? Do they have the same meaning? By the way, my favorite is 3b which can do with or challenge all of 1a. , 2a, and 3a. ♦♦♦ Sorry to add this: I advise him to come early.→ What I advised him was to come early. What I advised him to do was to come early. (I guess : Using the “to do” here is grammatically correct, but omitting it can also be grammatically correct and concise? ) Which is grammatically correct? and better?