Table 1.

Search strategy.

Search engine	Keywords
Pubmed	(((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“language learning” OR “second language” OR “foreign language” OR “foreign language learning” OR “second language learning”)))
Science direct	(((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“language learning”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“second language”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“foreign language”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“foreign language learning”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“second language learning”))) AND NOT (((“high school” OR “university” OR “college”)))
Scopus	(((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“language learning”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“second language”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“foreign language”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“foreign language learning”))) AND NOT (((“high school” OR “university” OR “college”))) (((“older adults” OR “elderly” OR “seniors” OR “third age”))) AND (((“second language learning”))) AND NOT (((“high school” OR “university” OR “college”)))