Prayer: What is the ruling for new Muslims who don’t know Arabic — must they learn it to pray?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: What is the ruling for new Muslims who don’t know Arabic — must they learn it to pray?

English:

Question #471:

How could foreigners, whether men or women, who embrace Islam and are not familiar with Arabic language perform their religious duties, including prayers, etc.? And basically, is there any need to learn Arabic in this case or not?

Answer #471:

It is obligatory to learn takbīrah al-iḥrām, the Fātiḥah, another chapter, tashahhud, and salām of prayer, and also everything for which Arabic recitation is a condition.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer