Sajda-e-Sahw

Q: Does a person have to perform sajdah sahw if he forgets to make qawmah and jalsah since both are waajib?

Q:

1. I was reading 4 rakaats fardh of Zuhr Salaah. After the first rakaat, I sat down and started reading tashahhud. I realised my error, but I completed the tashahhud, stood up and after the second rakaat did the tashahhud again and completed the rest of my salaah as normal. I did a sajdah sahw at the end, but I didn't recite the tasbeeh in the sajdahs. Is my salaah valid?

2. Previously, I was also reading 4 rakaat fardh of another salaah. In the second rakaat, after reading Surah Fatiha, I untied my hands to go in ruku. I quickly realised my mistake, tied my hands again and read a surah and continued the rest of the salaah as normal. Was I meant to read sajdah sahw in this situation?

Q: While sitting and performing salaah, I mistakenly tied my hands after coming up from the sajdah of the second rakaat instead of placing my hands on my lap for tashahhud. Does sajdah sahw become compulsory, like it would be compulsory if I were standing and performing salaah and stood up by mistake and then sat down?

Q: I was reading witr salaah and sat in tashahhud for the third rakaat. After reciting the tashahhud, I went into the fourth rakaat by mistake. On completing the fourth rakaat, I made salaam and sajdah sahw. Is my witr valid? Also, what is the ruling in the case where I forgot to sit in the third rakaat for tashahhud?

Q: I was leading the zuhr salaah and mistakenly performed five rakaats. At the end of the salaah, we performed sajdah sahw. Is the salaah valid?

Q: I missed one rakaat of jamaat salaah. I would like to know if sajdah-e-sahw should be made or not in the following cases after the Imaam made salaam to end the salaah:

1. I made one salaam on the right and then stood up to complete the missed rakaat

2. I made both salaams on the right and left and immediately stood up to complete the missed rakaat

3. I made both salaams and sat in the same position, and after one minute I stood up to complete the missed rakaat.

Q: If I recite alhamadu mistakenly before attahiyyaat in the last sitting and then do sajda-e-sahw, after sajda-e-sahw if I again mistakenly recite alhamadu before attahiyyaat, do I need to do sajda-e-sahw again or my prayer is valid without it?

Q: I was performing four rakaats of sunnah muakkadah and I had to do sajdah sahw but I forgot to do it. Should I redo my salaah?

Q: For Asr Prayer, if I mistakenly performed 5 rakaats instead of 4 rakaats, how do I correct the prayer? Do I need to perform Sajdah Sahw or repeat the salaah?

Q:

1. If I am praying 4 rakah salah and in the last rakah I doubted whether I prayed 4 or 5 rakah... as there is no 5 rakahs so I base myself on 4 rakahs and complete my prayer without doing sajda e sahw...is my prayer is valid?

2. Do I have to do sajda e sahw in this situation?