男(nán) - male, man in Mandarin

男 is the everyday word for male, and in modern Mandarin it is almost always bound: you meet it inside 男人 (a man), 男孩 (a boy), 男生 (a male student), 男朋友 (a boyfriend). On its own it appears mostly on signs and forms, where 男 marks the men's toilet and the male box on a questionnaire.

The pairing to learn alongside it is 女 (nǚ, female). The two run together through the language in exactly the way English pairs man and woman: 男人 and 女人, 男孩 and 女孩, 男朋友 and 女朋友. Learn them as a set and you get a dozen words for the price of two.

The trap for an English speaker is reaching for 男 where you want a whole word. "He is a man" is 他是男人, not 他是男. The character is a modifier far more often than it is a noun standing alone, so if you find yourself using it by itself outside a form or a sign, you probably want 男人 or 男孩 instead.