French language Q&A Forum

Q-)   Choisissez la bonne réponse:

"Nous téléphonons à ami de Nathalie." 

              Ou                               

"Nous téléphonons à l'ami de Nathalie."

From the above two sentences, which one is correct...also please provide me with the appropriate reason for the correct answer.

et n'est pas toujours pas revenu. My question is in regard with first (Pas), should it be there? if so, why?. Also, I verified with the audio file, it is not there. 

I am a beginner who wants to learn how to speak french well. What do you think is the best way to start?