Al-Jazeera offers a grammar test. There are a couple of pitfalls. So, reason enough to take a look at the most important Arabic grammar topics.
Hayya حَيَّ is used in the call of the Muezzin: Come to prayer! حَيَّ عَلَى الصَّلاةِ. It is a special word type: a Ism al-Fial (اسم فعل).
Some expressions in Egyptian Arabic can be very tricky. They are all related to the word ma - ما.