The World Federation One Stop Fiqh

Ruling 1185

In nine situations if one doubts about the number of rakʿahs in a four rakʿah prayer, he must think [about the doubt]; then, if he becomes certain or he supposes that a particular possibility is correct, he must act according to that possibility and complete the prayer; otherwise, he must act according to the instructions that will be mentioned later. The nine situations are as set out below.