聊(liáo) - to chat, to talk casually in Mandarin

聊 is chatting: light, unhurried talk with no agenda. It is friendlier than 谈 (to discuss, often formal) and broader than 说 (to say). 我们聊聊 is a warm invitation; 我们谈谈 sounds like a meeting.

In practice it usually arrives as 聊天, where 天 is a dummy object, so 聊天 means to chat in general and bare 聊 takes a real topic or a duration: 聊工作, 聊了两个小时. You can also split the compound: 聊聊天, 聊了一会儿天.

One false friend to sidestep: 无聊 is built on this character but means bored or boring, not "no chatting". And the reduplicated 聊聊 softens a request the way "have a quick word" does in English, so it is a genuinely useful politeness tool.