The aim of this paper is to investigate how Arabic native speakers (non-native speakers of English) interpret English ambiguous sentences. It has been recognized that Arabic native speakers encounter problems with English sentences which involve structural ambiguity. Sixty subjects participated in the experiment. All were university students specialized in English. The subjects were given ambiguous sentences contain prepositional phrases, relative clauses, etc. For instance, prepositional phrases like ‘the girl hit the boy with the book’ in which the prepositional phrase (PP) can be attached either to the verb phrase (VP) or to the preceding noun phrase (NP). It has been recognized that the students face difficulty in interpreting ambiguous structure and generally take the general meaning which can be understood from the sequence of words.