I am currently living in Turkey, and here there are two important differences. Firstly, the imams in all mosques pray Taraweeh four rak‘ahs by four. What should I do? Should I follow the imam or pray Taraweeh at home? Will the reward of having spent the entire night in prayer be recorded for me if I pray Tarweeh with twenty rak‘ahs?

The second difference is that before Ramadan, the adhaan for Fajr was at 4.28, but now the adhaan for Fajr is at 3.22, and the iqaamah for Fajr prayer in the mosque is after 4.30. When should I stop eating and pray Fajr?


Praise
be to Allah

Firstly: 

The Sunnah with regard to Taraweeh prayer
is to say the tasleem after every two rak‘ahs. 

With regard to praying it four rak‘ahs by
four, this is contrary to what is preferable, although a number of the
scholars regarded it as permissible, and others regarded it as mustahabb, as
is the view of the Hanafis. We have previously discussed the differences of
scholarly opinion concerning this matter in the answer to question no.
195355. 

If the imam does something that is valid
according to some of the scholars, or based on his own ijtihaad, or
following the opinion of a scholar, or because he thinks that it is correct,
then his prayer is valid and the one who is praying behind him must follow
him. 

Praying (Taraweeh) in the mosque with the
imam is better, and if you pray with the imam until he finishes, the reward
of spending an entire night in prayer will be recorded for you. 

See the answers to questions no.
45781 and 65501 

 Secondly: 

With regard to the difference in the time
of the adhaan for Fajr – in Turkey – between how it was before Ramadan and
how it is in Ramadan, the reason for that is that our Turkish brothers delay
the adhaan throughout the year so that they can pray Fajr when it is very
light, as is recommended according to the Hanafi madhhab, but they give the
adhaan for the correct time of Fajr in Ramadaan so that people can stop
eating when dawn breaks. 

Hence you have to stop eating when you
hear the adhaan, and you have to pray Fajr with the congregation in the
mosque. 

For more information, please see the
answer to question no. 66202 

And Allah knows best.