1. “Flat” 作形容词用，可以表示 “水平的，平坦的”。

This table is flat.

This bungalow has a flat roof.

2. “Flat” 作副词用，可以表示 “水平地”。

This book is lying flat.

I have to lie flat on my belly after hurting my back.

3. “Flat” 作形容词用，可以表示 “缺乏热情的，平淡的”。我们可以用 “feel flat” 表示某人 “无精打采；感到无聊；情绪低迷”。

I feel flat because my phone doesn't work.

She left me feeling flat with her harsh words.

I think the story of that movie was flat.

4. “Flat” 作名词用，可以表示 “公寓，单元房”，相当于 “apartment”。

I live in a flat in London.

He'd rather live in a house than a flat.

5. “Flat” 作副词用，放在一段时间后，可以表示 “刚刚好，正好”。

You can drive to my house in five minutes flat.

He cooks pancakes in a minute flat.