Lisān al-‘Aarab (لسان العرب), the famous dictionary of Classical Arabic, contains 9273 roots (and 4,493.934 words). A huge playground for people who are passionate about Arabic such as…
مَحْمُود عَبْد الرّازِق جُمعة
The man who tells native Arabic speakers what mistakes they make.
Tenses in Arabic are easy compared to other languages. The Arabic verb basically knows only two different (morphological) forms: the present and past tense.