04
The verb
باب الأفعال
Verbs are three: past, present (mudari), and command. The past is built open on the last letter: kataba. The command is built stopped: uktub. The present is the one that i'rab moves — it can be raised, installed, or cut (jazm).
The present is known by one of four letters on the front: a-, na-, ya-, ta- (I, we, he, you/she). Teachers call them anaytu.
The matn
الْأَفْعَالُ ثَلَاثَةٌ: مَاضٍ، وَمُضَارِعٌ، وَأَمْرٌ.
Verbs are three: past, present, and command.
ماض
Past
The act is done. Last letter is fatha when nothing extra is stuck on: كَتَبَ.
مضارع
Mudari
The act is not finished. This is the verb whose ending moves.
أمر
Command
A request to do it: اُكْتُبْ. Built, not declined, in the basic form.
Quran
96:1
اقْرَأْ is a command. يَقْرَأُ would be present. قَرَأَ is past. Same root. Three chairs.
The ten forms (I–X) tell you the mould of the verb. This chapter tells you its tense. You need both.