90% of the time, speakers of English use just 7,500 words in speech and writing. These words appear in red, and are graded with stars. One-star words are frequent, two-star words are more frequent, and three-star words are the most frequent.
as a determiner (followed by a noun, but not by a pronoun): Both children are at school.
as a predeterminer (followed by a word such as “the,” “this,” “his,” etc.): I like both these pictures. ♦ Both her children are boys.
as a pronoun: Both arrived at the same time. (followed by “of”): ♦ Both of them are learning English. (after a noun or pronoun subject): ♦ The twins both have black hair. (following a pronoun object): ♦ I like them both. (after a modal or auxiliary verb, or after the verb “to be”): ♦ We can both speak Spanish. ♦ They are both good singers.
in the expression both...and...: a method that is both simple and effective