I have been living abroad for long time, can I still combine my prayers?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The majority of the Muslim scholars are of the opinion that whoever intends to stay four days or more in a given place should pray complete prayers without shortening them since the rulings of the resident person apply to him. He should also fast (if it is Ramadan) and should not leave it by reason of journey. This is the opinion of Imams Ahmad, Maalik, ash-Shaafi’i and Abu Thawr.

Imam Ath-Thawri and the Hanafi School of jurisprudence are of the opinion that if one intends to stay fifteen days or less including the day when he starts his journey, then he can pray the traveler's prayer [i.e. he can shorten and combine the prayers]. But if he intends to stay more than fifteen days he has to perform complete prayers.

No doubt, the students who are studying in foreign countries stay more than four days, so they should perform complete prayers.
As for the Fatwa of some scholars that students can pray the traveler's prayer, it contradicts the opinion of the majority of the Muslim scholars; so it is not the preponderant opinion.

Imam Ibn Taymiyyah said: “If a traveler intends to stay at a place for four days or less he can shorten his prayers as the Prophet did when he entered Makkah. He stayed there four days and shortened his prayers. The scholars differed concerning a traveler intending to stay more than four days. In order to be on the safe side, it is better to perform complete prayer.

If one does not know definitely how many days he is going to stay and would always say: “I will leave today or tomorrow,” then he may perform the traveler’s prayer continually. The Prophet stayed in Makkah more than ten days, and he shortened his prayers and he stayed in Tabook for twenty days and he shortened his prayers.”

Finally, we would like to inform you that whenever shortening the prayers is permissible for a traveler, combining them becomes permissible for him, and whenever it becomes prohibited for him to shorten prayers, it becomes also prohibited for him to combine them.

For more benefit on the ruling on shortening and combining the prayers, please refer to Fataawa 362857, 83821, 90615, 90113, 88402, and 350368.

Allah knows best.