English and Latin just work differently here, in that English uses auxiliary/supporting verbs in questions (do, did, etc. in addition to the "important" verb that contains the crucial information), whereas Latin doesn't. Same thing in negative sentences; English says "doesn't", "didn't", etc. in addition to the "important verb", while Latin uses no such supporting verbs.
So in Latin you say:
Quid misisti?
Misistine litteras?
Non misi litteras.
Which are, more or less word for word:
What sent you?
Sent you the letter?
I sent not the letter.
But of course in normal contemporary English the translations will be:
What did you send?
Did you send the letter?
I didn't send the letter.