“…Therefore, it is an economic investment for an individual to learn one or more other languages. Since the 1980s, various studies have supported empirically that language, as human capital, plays a critical role in the determination of earnings (Carliner, 1981;Shapiro & Stelcner, 1981;Grenier, 1987;McManus, 1985;Chiswick & Miller, 1995, 1998, 1999, in Chiswick & Miller, 2007, especially for immigrants (Dustmann, 1994;Dustmann & Fabbri, 2003;Leslie & Lindley, 2001;Shields & Price, 2002;Bleakley & Chin, 2004;Aldashev et al, 2009;Yassin et al, 2020). Thus, Zhang and Grenier (2012) concluded that other things being equal, the more fluent an employee, the higher the wage he or she can get.…”