Salaah

Performing Tahajjud Salaah in pairs of 2 and 4

Q: We know that praying 8 rakaah in tahajud is sunnah but there is no limit on the number of rakaah.

My question is should we pray these 8 rakaah in pairs of 2 or 4 and if we want to pray in pairs of 4 for example 4+4 is 8 so should we recite another surah after fatiha in the third and fourth rakkah because we know that reciting a surah after fatiha in the third and fourth rakaah is wajib in sunnah e muakadah and ghair e muakadah.

Children standing next to their fathers in the saff during salaah

Q: I wanted to ask the mas'alah regarding children standing in saffs with the men. I always knew that small boys should stand behind the saffs of the men. However, I have noticed a trend of small boys standing next to their fathers.

It just worries me and I am inconvenienced at these small boys standing beside me in the saff. Please advise and guide as to what is correct according to Shariah.

Doubts in salaah

Q: Most of the time, I feel during Salah, I didn't do sujood or didn't recite Surah Fatiha, or didn't say tashahhud or didn't pray complete rakaats so I most of the time do Sajda Sahw. Am I doing it correct?