does your brother speak English do your brothers speak English what is the difference in both

In the first sentence the subject is singular "brother" so the helping verb is singular "does" But in the second sentence the subject is plural "brothers" so the helping verb is plural "do".

in the first sentence only one brother is mentioned in the second sentence two or more than two brothers are mentioned

Does your brother speak English? kya tumhare bhai english bolte hai? (when ask about one brother then we use 'does') Do your brothers speak English? kya tumhare bhai (Brothers) english bolte hai?(when ask about 2 or 3 brother then we use 'Do')