**1. Introduction**

The researchers have been attempting to identify the influences or variables that influence foreign language acquisition. The researchers even wanted to know how to tell the difference between good and unsuccessful students. Since achievement is determined by a number of factors, researchers emphasized the importance of learning. Many researchers have identified learning strategies, and they all agree that active learners employ a variety of strategies and techniques to effectively solve problems they encounter when learning or acquiring a language. Investigations into the use of learning strategies by bi- or monolingual students have been conducted all over the world, especially in English-speaking countries.

The aim of this study is to look into the differences in learning strategies used by monolingual and bilingual foreign language learners when learning a language. It also aims to see whether factors like ethnicity and proficiency have an effect on the use of learning techniques.

In certain parts of the world, the number of people who can speak more than one language has grown in recent years. According to [1] about 70% of the world's population is bilingual. This emphasizes the importance of researching the role of bilingualism in the teaching and learning of a foreign language. Bilingualism is a practice that exists in other countries around the world, including Iran. Furthermore, various parts of the world speak a mixture of languages and dialects. As a result, there could be gaps in acquiring a foreign language between monolingual and bilingual students. In Iran, English is a foreign language, and learning a

foreign language in order to communicate with people from other countries is a must in a developing world.

The controversy about whether learning two languages benefits or hinders the production of either language has become one of the most fiercely pursued research questions by contemporary language scientists. During almost every waking minute of our lives, we are surrounded by words. We use language to express ourselves, interact with others, and associate with our history, as well as to comprehend the world around us For certain people, this diverse linguistic world includes not only one, but two or three languages. In reality, bilingual or multilingual people make up the vast majority of the world's population. In a 2006 European Commission poll, 56 percent of respondents said they could communicate in a language other than their mother tongue. Millions of people in the United States speak a language other than English in their daily lives, whether at work or in school. Neither Europe nor the United States are isolated. According to the Associated Press [2], up to 66 percent of the world's children are bilingual. 3 Researchers have been able to look further into the brain to explore how bilingualism communicates with and affects the neural and physiological processes thanks to scientific advancements in recent decades.
