The 'm'' is an abbreviation for 'me' which means 'me' or 'to me', the 'a' is the third person singular of the verb 'to have', 'avoir. Hope this answers your question, Jason.
The « m' » is the indirect object of the verb. Both direct and indirect object pronounced are placed before the conjugated verb. In this case, it is the auxiliary verb "avoir" used in the compound tense.
The object of the verb 'reply' is what you say in your reply e.g. He replied yes. You have to have the word 'to' to show you are talking about the other person. 'He has not replied to me' is correct because 'He has not replied me' would mean 'He has not said "me" in reply'.
Some English verbs require "to" with an indirect object. Others do not. For example:
- He did not reply to me (not "reply me")
- He did not respond to me (not "respond me")
- He did not answer me (not "answer to me")
If you are using a version that has word-tiles for you to arrange, then you will have to select the best answer you can from what you are given.