'AAMEEN:

It is sunnah to say Aameen when a person finishes recitation of Surah Fatihah. If he is praying alone he should say "Aameen" in silence and if he is praying with congregation behind an imam then he should say Aameen fairly loudly when the Imam finishes saying the last verse of Surah Fatihah. When saying 'Aameen the voice of the whole congregation should resound at the same time.

There are many hadiths which prove that saying Aameen aloud is Sunnah of the Holy Prophet(saw) and it was the regular practice of the companions. We will mention a few of these hadiths here.

a) Naeem al Mujammar said: "I prayed behind Abu Hurairah(ra). He recited Bismillah hir-rahma nir-ra,heem, then he recited surah Fatihah, and when he reached walad dal-leen, he said, 'Aameen' after it and the people behind him said Aameen...." (Bukhari).

b) Abu Hurairah(ra) reported that the Messenger of Allah(saw) said: " When the Imam Says 'Ghayril Maghdubi alayhim walad dal-leen', all of you should say, 'Aameen', because the Angels say Aameen and the Imam says Aameen. And whosoever says Aameen and his voice blends with that of the angels he would be forgiven his sins." (Ahmed, Abu Dawud, Nisai)

c) Aisha(ra) reported that the Messenger of Allah saw) said: "Jews are more envious of Muslims in two things (a) our greeting someone with Assalamu 'alaykum and (b) saying Ameen (aloud) behind the Imam" (Ahmad, Ibn Majah).