Is it permissible to perform the Tarawih prayer four continuous rak'ahs with a single taslim, with a tashahhud between the two rak'ahs? And is it permissible for someone who intended to pray 'Isha to follow them, then leave the congregation after the second rak'ah to pray his prayer secretly, or should he complete it with them despite their audible recitation?

The majority of scholars permit performing Tarawih prayer with four rak'ahs and a single taslim, with the following details:

- Hanafis: Tarawih prayer is valid if performed entirely with one taslim, provided that one sits after every two rak'ahs. However, intentionally doing so is disliked because it deviates from what is traditionally transmitted. If one does not sit after every two rak'ahs and performs a single taslim, the obligatory prayer becomes invalid according to Muhammad, but not according to Abu Hanifa and Abu Yusuf. The most sound opinion is that it is permissible with one taslim.

- Malikis: It is recommended to perform taslim after every two rak'ahs, and it is disliked to delay the taslim until after every four rak'ahs. The best approach is to perform taslim after every two rak'ahs, even if one intends to perform four.

- Shafi'is: The prayer becomes invalid if four rak'ahs are performed with a single taslim intentionally and with knowledge. Otherwise, it becomes a general supererogatory prayer (nafl mutlaq).

- Hanbalis: The best way to perform supererogatory prayers (tatatwu') is in units of two (mathna) both at night and during the day. However, if one performs more than that, it is valid, even if it is eight rak'ahs at night or four during the day. This is the adopted view of the school. If one performs more than two rak'ahs at night, it is disliked according to the soundest opinion within the school.

Regarding performing 'Isha prayer behind someone praying Tarawih: It is valid according to the Shafi'is, but they do not permit performing Tarawih prayer with four rak'ahs and a single taslim. Therefore, if the Imam stands for the third rak'ah in Tarawih, the congregant praying 'Isha must separate and complete their prayer alone.