Should the one who is praying behind the imam recite al-Faatihah or listen to the recitation of the imam?

Reciting al-Faatihah is one of the pillars or essential parts of the prayer for the imam, the one who is praying behind an imam and the one who is praying on his own. 

With regard to the pause that some imams leave after reciting al-Faatihah, it is not long enough for the one who is praying behind the imam to recite al-Faatihah; rather it is only a brief pause that serves to separate between the recitation of al-Faatihah and the recitation of another soorah. 

 Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: 

The pause between the recitation of al-Faatihah and another soorah was not narrated from the Prophet (blessings and peace of Allah be upon him), despite the view of some of the fuqaha’, that the imam should pause so as to allow those praying behind him to recite al-Faatihah. Rather it is a brief pause that is intended for one to catch one’s breath on the one hand, and to allow the one who is praying behind the imam, on the other hand, to start to recite (al-Faatihah) and he should complete it, even if the imam is reciting, because it is a brief pause, not a long one. End quote.

Fataawa Arkaan al-Islam, p. 323-324 

If the imam does not pause for a long time after reciting al-Faatihah, then the one who is praying behind him has to recite al-Faatihah, even if that is at the same time as the imam is reciting the other soorah, because this is what was the Prophet (blessing and peace of Allah be upon him) instructed his companions to do in Fajr prayer. 

Abu Dawood (823) narrated that ‘Ubaadah ibn as-Saamit (may Allah be pleased with him) said: We were behind the Messenger of Allah (blessings and peace of Allah be upon him) in Fajr prayer. The Messenger of Allah (blessings and peace of Allah be upon him) recited, and he found it difficult to recite (due to interference). When he finished praying he said: “Perhaps you were reciting behind your imam?” We said: Yes, O Messenger of Allah. He said: “Do not do that, apart from the Opening of the Book (al-Faatihah), because there is no prayer for the one who does not recite it.” 

Classed as hasan by al-Tirmidhi; classed as saheeh by al-Bayhaqi, al-Khattaabi and others. This is a clear statement that it is obligatory for the one who is praying behind an imam to recite al-Faatihah in a prayer in which recitation is done out loud. 

Shaykh Ibn Baaz said: If the imam does not pause, the one who is praying behind him has to recite al-Faatihah even if that is when the imam is reciting (the other soorah), according to the more correct scholarly view.

End quote from Fataawa ash-Shaykh Ibn Baaz, 11/221 

Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: 

If it is asked: if the imam does not pause, when should the one who is praying behind him recite al-Faatihah? The answer is: he should recite al-Faatihah when the imam is still reciting, because the Sahaabah used to recite al-Faatihah with the Messenger (blessings and peace of Allah be upon him) and he said: “Do not do that except with the Essence of the Book (al-Faatihah), because there is no prayer for the one who does not recite it. End quote. 

Fataawa Arkaan al-Islam, p. 322 

With regard to the words of Allah (interpretation of the meaning): “So, when the Quran is recited, listen to it, and be silent that you may receive mercy” [al-A‘raaf 7:204], this is general in meaning, except when one has to recite al-Faatihah, in the sense that it is obligatory to listen attentively to the imam’s recitation of Qur’aan in prayer, except when the one who is praying behind him is reciting al-Faatihah only. This is based on the words of the Messenger (blessings and peace of Allah be upon him): “Do not do that, apart from the Opening of the Book (al-Faatihah), because there is no prayer for the one who does not recite it.” And that was in Fajr prayer, which is a prayer in which recitation is done out loud, as is well known. 

So the one who is praying behind the imam is enjoined to listen attentively except when he is reciting al-Faatihah. 

And Allah knows best.