In Arabic there are only three types of words:
- Ism - nouns. إسم
- Fi'l - verbs. فعل
- Harf - particles. حرف
If a word has the letters "al" ال attached to it then automatically you know it is an ism. Also, if it has a tanween i.e. the sounds "an / in / un" then again it has to be a noun. There are other ways of identifying it, as well as for the verbs and particles, but we won't go into that. Nouns don't have any tense. An example would be baitun (a house) or al-walad (the boy).
A fi'l is a verb and in Arabic they have two tenses:
- al-Maadi - perfect tense. الماضي
- al-Mudaari' - imperfect tense. المضارع
In English we're used to having three tenses: past, present and future. In Arabic al-maadi = the past tense. And al-mudaari' = both the present and future tenses.
Most verbs have three root letters. Eg. fa'ala فعل. Here the root letters are a faa, 'ain and laam.
You can then add on other letters to change the meaning slightly.
You can change the number, i.e. make it dual or plural.
You can also change the gender, i.e. male or female.
You can also change the person, i.e. third (eg. He did), second (eg. You did) or first (eg. I did).
A harf is a particle and they don't have any set meaning. There meaning is determined by their context in the sentence. They usually stay the same and do not change.