Yo

Yo is an English slang interjection, commonly associated with American English. It was highly popularized after being used commonly in Philadelphia, Pennsylvania since the 1940s.

Although often used as a greeting, yo may come at the end of a sentence, often to direct focus onto a particular individual or group or to gain the attention of another individual or group. It may specify that a certain statement that was previously uttered is more important, or may just be an "attention grabber".