Muqtadi saying the takbeer when moving to different postures
Q: Is saying transitional takbeer (Allahu Akbar) when going to ruku, sujood, qiyaam obligatory upon the individual praying behind an imam or can he just follow the imam.
I have performed many prayers behind the imam and I thought I wasn’t obligated to say the takbeer besides takbeer al ihram. Would my previous prayers be invalid otherwise even if I were unaware?