One of the main aspects that attract attention in Arabic grammar is the ways of subject expressions of the nominative sentences. The main purpose of the article is, first of all, to give the definition of subject in Azerbaijan and Arabic languages, generalize the distinctive features and differences and analyze the ways of subject expressions of the nominative sentences in Arab language. The ways of subject expressions of the nominative sentences in Arabic language are also analyzed in the article. The information about the main members of the nominal sentences, the definitions of the subject and predicate in Arab grammar were given, then the ways of subject expressions of nominal sentences were analyzed. The concept of nominal sentence in arabic traditional grammar, the sentence structure of nominal sentences in comparison with the verbal sentences were also explained in the investigation. The nominal sentences with a subject expressed by personal nouns and those types of sentences were analyzed with the help of examples. Coordination between the subject and predicate in nominal sentences, the place of the subject which is often used first and also the grammar rules which give the opportunity to the predicate to be used at the beginning of the sentence were also analyzed in the article. In addition the nominal sentences with the subject expressed by common nouns were analyzed, the concepts of certainty and uncertainty in nominal sentences were also considered. It was found that the subject in Arabic language is often expressed by pronouns, so the ways of subject expressions by demonstrative, personal, relative pronouns were shown. Those ways were shown with the help of examples, the difference between the noun phrases and nominative sentences were shown, the easy ways of transformation of noun phrases into nominative sentences as well as the transformation of nominative sentences into noun phrases were also demonstrated. The article reveals that the subject can be expressed not only by words, but also by word combinations, different attitude to this problem in Arabic linguistics was revealed. It is stated that analyses of nominative sentences in Arabic language should be based on the grammar of the native language. It is also shown that the subject could be also expressed by infinitive phrases. The analysis carried out in comparison with the Azerbaijani language makes it possible to come to the following conclusions: In Azerbaijan language declarative sentences with the predicate expressed by a verb often reflect time, but there is no expression of time in declarative sentences with the predicate expressed by a noun. In Arab language the meaning of time belongs only to the verb. But it should be noted than the capasity of the verb in Arab language is wider. The verb in Arab language can express time, quality, sex, person. That’s why there is no need to use the personal pronoun. According to the ways of predicate expressions in Azerbaijan language it is possible to distinguish types of sentences. If the predicate is expressed by a name (noun, adjective, etc.) the sentence is called nominative, if it is expressed by a verb it is accepted as the predicative sentence. But in Arabic language it depends on the word standing at the beginning of the sentence. According to that principle if the sentence begins with the noun it is analyzed as a nominal sentence, if it starts with a verb, it is accepted as predicative sentence. In Azerbaijan language the subject can be used at the beginning, in the centre or at the end of the sentence. But in Arabic language the subject is normally used only at the beginning of the sentence (if we do not take into account a few exceptions). To the opinion of Arabic linguists the meaning of the word is “to begin”. So it is more advisable to use the subject at the beginning of the sentence. But in Azerbaijan language the message given by a sentence is taken into account. If there is a movement in that message the sentence is accepted as predicative sentence. As for example: the verb “darab?” – “vurdu”. This verb can be accepted as the sentence “He hit”. The verb has already informed us that a man is alone and he hit somebody. But a personal pronoun was hidden inside the verb. In the sentence “?hm?d Muradı vurdu.” it begins with the noun, so it is called a nominative sentence. But the predicate of the sentence could also be analyzed separately as a predicative sentence. There are different ways of subject expressions in Arabic language. The subject in nominative sentences is definite, but the predicate in those sentences is indefinite. It should be noted that in Arab language definite and indefinite grammar categories are widespread. So if both sides of the sentence are only in definite or indefinite category so the sentence could be easily changed into the word phrase. One of the main problems in Arab language is the structure of the sentence. The subject in the sentence is used before the predicate. In case of inversion the words “vardır”, “mövcuddur” are used. In Arabic language the predicate also has different ways of expression. As for example nominal predicates, etc. Because being and existence are the concepts related to the noun. The noun can talk about itself, its existence. It is one of the most distinguished differences between a noun and a verb. As for example: the noun “a book” includes much more information than any other verb. Complex sentences with the preposition “enne” in Arab language are often expressed by complex sentences with subjective and objective subordinate clauses in Azerbaijan language. So it is possible to translate them with the help of simple phrases and sentences. The opportunities of the Azerbaijani language give the possibility to melt the preposition inside the sentence, and translate it not in a complex but a simple way.