Method of Salaah

Forgetting to sit for the last qa'dah

Q: A person was performing a four rakaat fardh salaah. After performing the fourth rakaat, he did not sit for the qa'dah but forgetfully stood up for the fifth rakaat. He then made ruku and sajdah in the fifth rakaat, sat for tashahhud and made salaam.

What is the status of his salaah? Is his fardh salaah valid or does he have to repeat his salaah?

When should the tasmee and tahmeed be recited?

Q: 

1. I am a student of deen. I wish to know whether the imaam and muqtadee should recite tahmeed in salaah? If they should recite it, then when should they recite it? Should they recite it while rising from ruku or while standing in qaumah? I have heard that there is a difference of opinion in the Hanafi Mazhab in regard to this mas’alah.

2. Should the munfarid recite tasmee and tahmeed or only tahmeed?

When should the tasmee and tahmeed be recited?

Q: I was always of the impression that the muqtadee should recite tahmeed in qaumah after the imaam completes reciting tasmee. However, I was lately informed by certain Ulama that the muqtadee should recite tahmeed at the same time that the imaam recites tasmee. I would like to know whether this is correct? I also wish to know whether all my past salaah are valid since I have always been reciting tahmeed in qaumah after the imaam completed reciting tasmee.