"Δεν απάντησα στην ερώτησή σου."
Μετάφραση:I did not answer to your question.
Would you consider adding "I did not reply to your question" which is more usual than " I did not answer to your question". If you wanted to use the latter then it is better to say " I did not answer your question".
The first suggestion is added. The second is reported as we can not edit the initial sentences.
Thanks Glavkos. To answer to means to be responsible to eg I don't have to answer to you, meaning you are not my boss I don't have to give you a justification. The second meaning is to answer to the cause, meaning to respond to an appeal. :-)
These are delicate variatons of meaning not easily understood from non-native speakers, are they?