Mullas and those under their toxic influence claim it is forbidden to supplicate to Allah in one’s own language other than Arabic during the Salat.
But contrary to this, the Prophet (ﷺ) said:
أَقْرَبُ مَا يَكُونُ الْعَبْدُ مِنْ رَبِّهِ وَهُوَ سَاجِدٌ فَأَكْثِرُوا الدُّعَاءَ
“The closest that a person can be to his Lord, the Mighty and Sublime, is when he is prostrating, so increase in supplication then.”
This is a strong proof that a person can offer supplication in his or her own language during the Sajdah (prostration). The Prophet (ﷺ) instructed Believers to increase supplication to the Lord in that particular state of worship. It is obvious that a non-Arab or someone who isn’t fluent in Arabic will be unable to fulfil this instruction if he or she is restricted to supplicating in the Arabic language only.