Definition
Used to describe a situation where you are sure you know something and feel very close to remembering it, typically a word or name.
話在嘴邊（很快記起來）
I know the actor's name; it's right on the tip of my tongue, but I can't quite recall it at the moment.
我知道那個演員的名字，就在嘴邊，但我一時想不起來。
I'm quite sure I've learned this word before; it's on the tip of my tongue.
我很確定我之前學過這個詞，就在嘴邊。
The advice I wanted to give you is on the tip of my tongue, let me think for a second.
我想給你的建議就在嘴邊，讓我想一下。