>交了很多朋友 交 in 交朋友 is short for 結交 (form relationship). Therefore, 交了很多朋友 means 'you formed many relationships with people who now are your friends >认识了很多朋友 认识 means 'to know'. 认识了很多朋友 means 'got to know many people who now are your friends' Comparing the two: 交了很多朋友 - formed relationships with many people --> became friends 认识了很多朋友 - got to know many people --> became friends Therefore, they both mean 'made many friends' >結识 is the combination of 結交 and 认识 >結识了很多朋友 - get to know and form relationship with many people --> became friends **Edit:** Puco4 wrote: >*maybe it is also possible to say 做朋友?* 做朋友' can mean 'befriend (+ object)' or 'being a friend to (+ object)' e.g. 我想跟他做朋友 (I want to befriend him/ I want to become a befriend to him); 我和他做朋友已經十年了 (He and I have been friends for ten years) You cannot say '我做了很多朋友' (I've been many friends). You have to say '我和很多人做了朋友' (I befriended many people) or (I've become friends to many people)