Undecided questions
How do I recognize al-masdar / what are arabic nouns?

try to add al altaarief it only fits on noun ( al masdar)

there are many types of almasdar
1 add م in the beginning of the tree letter verb = ( ضَرَب = مَضْرَب )
2 "Almarah" is used to show how many times an action is repeated. = ( قَرَأ = قَرْأة )
3 "Alhai'ah" is used to show the way a verb is done. = ( مشى = مِشْيَة )

The problems you are having with the infinitive, active and passive participle are quite simple. In morphology you learn that all the derivatives derive from the radicals of the past tense.
EXAMPLES:
1- If the verb has 3 letter root the infinitive is derived from hearing, which means you will have to build a good vocabulary before trying to form it properly. As for the participles they are easily formed on the patterns: فاعل for the active participle, and مفعول for the passive, without any changes if the verb root is strong.
2- If the verb is 3+ letter root the participles are formed in two steps:
A- Replacing the initial of the present tense with مـُ -notice the Dammah-
B- Vowelizing the second to last letter with Kasra for the active participle, and with Fat'ha in the passive.

That concludes the answer to your question. If you want to learn more about this subject or feel free to contact me lessons.

Ustadh Ehab

In Arabic there are two types of nouns:

A- Defective [جامد].
The defective noun is either person اسم ذات or abstract اسم معنى.

B- Derivitive [مشتق].
The derivitive nouns are many, here are some examples:
1- المصدر
2- اسم المصدر
3- المصدر الصناعي
4- اسم الهيئة
5- اسم الفاعل
6- اسم المفعول
7- اسم التفضيل
8- اسما الزمان والمكان
9- اسم الآلة
10- اسم المرة

Ustadh Ehab

actually al-masdar has common things with its verb:

**al-masdar and its verb share the meaning

**al-masdar and its verb share the same letters .ALL the letters that exists in the verb exists in al-masdar .

**the verb can be present ,past or imperative while al-masdar is abstracted form time .

hope that helps :)