関連ワード:  why is it hard to learn a second language    why is it harder to learn a second language as an adult    why is it hard to learn a new language    why is it hard to learn a new language as an adult    why is it harder to learn a new language when you are older    why is it hard to learn another language    why is it hard for me to learn a new language    why is it harder for adults to learn a new language    why is it so difficult to learn a new language in adulthood psychology    why is it so difficult to learn a new language in adulthood  
結果 : why is it hard to learn a second language