Taraweeh prayer is two by two rak’ahs
Question

                Some imams in Taraweeh put four or more rak’ahs together with one tasleemah, without sitting between each two rak’ahs, and they claim that this is Sunnah. Is there any basis for this action in sharee’ah?.
Praise be to Allah.
    This action is not prescribed in sharee’ah, rather it is 
    makrooh or haraam according to most scholars, because the Prophet  
    (peace and blessings of Allaah be upon him) said: “The night prayers are two 
    by two.” Saheeh – agreed upon, from the hadeeth of Ibn ‘Umar (may Allaah be 
    pleased with him). And it is proven that ‘Aa’ishah (may Allaah be pleased 
    with her) said: The Prophet  (peace and blessings of Allaah be upon him) 
    used to pray eleven rak’ahs at night, and say the tasleem after each two 
    rak’ahs, and he would pray Witr with one rak’ah. Saheeh, agreed upon. And 
    there are many similar ahaadeeth. 

    With regard to the famous hadeeth of ‘Aa’ishah, which says 
    that “the Prophet  (peace and blessings of Allaah be upon him) used to 
    pray four rak’ahs at night, and do not ask how beautiful and how long they 
    were, then he would pray four, and do not ask how beautiful and how long 
    they were”, the hadeeth is agreed upon – the answer is that he said the 
    tasleem after each two rak’ahs; it does not mean that he would follow four 
    rak’ahs with one salaam, because of the hadeeth quoted above. And it is 
    proven that he  (peace and blessings of Allaah be upon him) said: “The 
    night prayers are two by two” as stated above. The ahaadeeth confirm one 
    another, so the Muslim is obliged to study all of them together and to 
    interpret those that are general in meaning by those that are more specific. 
    And Allaah is the Source of strength. End quote. 

    Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on 
    him)