3 sentences

1. 他在椅子上加了一个软垫。

   tā zài yǐ​zi shàng jiā le yī gè ruǎn diàn.

   He added a soft cushion to the chair.

   Source: Dong Chinese Dictionary

2. 桌腿有点晃，拿块纸头垫一下。

   zhuō tuǐ yǒu​diǎn huàng, ná kuài zhǐ​tóu diàn yī​xià.

   The table leg is a bit wobbly; use a piece of paper to steady it.

   Source: Dong Chinese Dictionary

3. 我没带钱包，你能不能先帮我垫一下？

   wǒ méi dài qián​bāo, nǐ néng bù néng xiān bāng wǒ diàn yī​xià?

   I didn't bring my wallet; could you cover for me first?

   Source: Dong Chinese Dictionary