concessive clause
noun [ C ] language specialized uk/kənˌses.ɪv ˈklɔːz/ us/kənˌses.ɪv ˈklɑːz/
让步从句
a clause, often beginning with "though" or "although", that expresses an idea that suggests the opposite of the main part of the sentence
The sentence "Although he's quiet, he's not shy" begins with a concessive clause. “Although he's quiet, he's not shy.”这句话是以让步从句开头的。