Du'aa during Salaah -
Reading Sunnah/Qur'aanic du'aas only in Salaah or whether one can read ones own
du'aas as in one makes du'aa in Arabic?

Answer: 

The
Fuqaha have written that in the final sitting posture after sending Salaawat
upon Rasulullah H
one is permitted to make any Dua in Arabic that resembles the Duas found in the
Quraan and Hadith. However, Duas that resembles the speech of people will not
be permitted even though it may be made in the Arabic language, such as saying
“Allahumam Zawwijni Fulaana - O Allah, let me be married to so and so.”

والصلاة
على سيدنا النبي صلى الله عليه وسلم في الجلوس الأخير والدعاء بما يشبه ألفاظ
القرآن والسنة لا كلام الناس (نور الايضاح)  

And allah ta’ala knows best

ANSWERED BY: Mufti Mohammed Desai 

CHECKED
AND APPROVED BY: Mufti Muhammed Saeed Motara Saheb D.B

Date:-  28 Jumadal Ula 1440 - English Date: 04 February 2019