Q: Assalamu alaikum.. What is the ruling of making Dua in native language during sujud after tasbih? Is there any difference between the one who is fluent in Arabic & the one who is not?
A: Wa ‘alaykum al-salam. As for the supererogatory adhkar and supplications of the prayer, they “are not to be translated into another language if you are unable to say them because they are not needed and if you do i.e. translate the supererogatory adhkar, the prayer is invalidated due to it i.e. the translation, being extraneous speech...”
It’s best to save translated supplications for outside of prayer. Allah knows best.
Source: -Kashshaf al-Qina’