As salamu alaykum Ustadh, if the imam is praying fast, can i say what he is saying (takbeer or other things) while he is saying it, because i might miss doing a obligatory action with the imam in the prayer like for example sitting between the two sajdah´s? BarakAllahu feek

Ustadh AbdulAziz al-Haqqan

If he is praying so fast that his salah is invalid dont pray behind him.