Wa alaykum salam wa rahmatuLlahi wa barakatuHu,
Five daily prayers are obligatory. Each consists of a certain number of rakahs, as follows:
1) Subh is a two rakah prayer [the morning prayer].
2) Zuhr is a four rakah prayer [the afternoon prayer].
3) Asr is a four rakah prayer [the mid-afternoon prayer].
4) Maghrib is a three rakah prayer [the after sunset prayer].
5) Isha is a four rakah prayer [the night prayer].
The emphasized supererogatory prayers that are offered along with the obligatory prayers (in Arabic they are called rawatib mu’akkadah رواتب مؤكدة) are as follows:
1) Two rakahs before subh.
2) Two rakahs before and after zuhr.
3) Two rakahs after maghrib.
4) Two rakahs after isha.
If one wishes he could also pray four rakahs before and after zuhr. Also, one may offer four rakahs before asr. And two rakahs before maghrib. One should also be punctual in performing witr. According to the Shafi’is witr is sunnah, while according to the Hanafis it is wajib.
(See: Mughni al-Muhtaj v. 1, p. 450-51)
And Allah knows best.
Shafiifiqh.com Fatwa Dept.