【正确答案】正确答案：Saussure was the first to notice the complexities of language. He believed that language is a system of signs. To communicate ideas, signs must be part of a system of signs, called conventions. He held that the sign is the union of a form (signifier) and an idea (signified) , and it is the central fact of language. By providing answers to questions concerning many aspects of language, Saussure made clear the object of study for linguistics as a science. Saussure exerted two kinds of influence on modern linguistics. First, he provided a general orientation, a sense of the task of linguistics which has seldom been questioned. Second, he influenced modern linguistics. Many of the developments of modern linguistics can be described as his concepts, i. e. his ideas on the arbitrary nature of sign, on the relational nature of linguistic units, on the distinction of langue and parole and of synchronic and diachronic linguistics, etc. Saussure's fundamental perception is of revolutionary significance, and it is he that pushed linguistics into a brand new stage and all linguistics in the twentieth century is Saussurean linguistics. That's why Saussure is considered being the father of modern linguistics.