1. You look like you are 18.
你看起来才18岁。(Nǐ kànqǐlái cái 18 suì。)

看起来 (kànqǐlái)：to look like

2. You sing karaoke.
你们唱卡拉OK。(Nǐmen chànɡ Kǎlā OK。)

卡拉OK (Kǎlā OK): karaoke

3. You leave the plastic covers on your remote control.
遥控器外面包着塑料膜。(Yáokònɡqì wàimiàn bāozhe sùliào mó。)

遥控器(yáokònɡqì): remote control
 

4. You've never kissed your mom or dad.
你从来没有吻过你的父母。(Nǐ cónɡlái méiyǒu wěn ɡuò nǐ de fùmǔ。)

吻 (wěn): to kiss

 5. You've worn glasses since you were in fifth grade.
你从五年级开始就戴眼镜了。(Nǐ cónɡ wǔ niánjí kāishǐ jiù dài yǎnjìnɡ le。)

戴眼镜 (dài yǎnjìnɡ): wear glasses