The Mandarin word for "friend" or "friends" is péngyou. It is made up of two characters: 朋 (péng) and 友 (yǒu), both of which mean “friend” and can be combined with other characters to express the many aspects of friendship.
Examples

    Tā shì wǒ de hǎo péngyou.
    他是我的好朋友
    他是我的好朋友
    He is my good friend.

    Nǐ yǒu méiyǒu nán péngyou?
    你有沒有男朋友?
    你有没有男朋友?
    Do you have a boyfriend?