بسم الله الرحمن الرحيم
السلام عليكم ورحمة الله وبركاته
Nouns in Arabic are all either masculine مذكر or femenine مؤنث . There is no neutered form "it" in Arabic. The easiest way to tell the difference is to pick what word is مؤنث and then all the rest are مذكر .
Rules for Recognizing a Feminine Noun إسم مؤنث
1. Feminine by Form: with a few exceptions, the word ends in a ta marbuTa ة or alif hamza اء or alif maqSura ى
2. City, Non-Arab country names: City names are feminine because they follow the gender of مدينة (city), Some Arab countries are feminine but you would have to learn these by memorization
3. Words referring to Females: Like the word for girl بنت does not end in ة but is feminine because it refers to a female. This includes proper nouns like names of women.
4. Non-human plurals: for example, the word book كتاب is a masculine singular noun. It would take a masculine singular adjective, such as beautiful جميل . However, in the plural form books كتب (pronounced kutub) it would take a feminine singular adjective such as beautiful جميلة .
So beautiful book is كتاب جميل (kitaab jameel)
And beautiful books is كتب جميلة (kutub jameela)
5. Parts of the body that come in pairs: such as hand يد or eye عين
6. Any exceptions that you just have to memorize: like sun شمس or soul نفس