It is common knowledge that Modern English (especially its American version) has become a language of international significance and is expanding its area of impact day by day. Naturally, Armenia could not remain unaffected. Bilingualism (Armenian and English), even trilingualism (including Russian) have doubled in our country in the last decade owing to the development of tourism, mixed marriages, growth in the number of international organizations and other factors.Bilingualism is closely related to a linguistic phenomenon in which the Armenian speech is complemented with English words, word combinations and even sentences. The reasons contributing to such phenomena are not only linguistic but also social-psychological. It is applied in most diverse social spheres – in the field of education in order to enhance one’s knowledge, in everyday speech to fill the vocabulary gaps and make some impression on the interlocuter, etc. Research suggests that code switching can contribute to borrowings from one language into another thereby enriching the Armenian vocabulary. On the other hand, if this process lasts long and encompasses larger masses it can distort the language and threaten the purity of the national language.