Level 5 · Advanced
To avoid: 以免 / 免得
Do X，以免 / 免得 + Bad Outcome
免得 (miǎnde) and 以免 (yǐmiǎn) both mean "so as to avoid": first the precaution, then the trouble being dodged — 出门早一点，免得堵车 "leave a bit early to avoid the traffic."
免得 is the everyday spoken one; 以免 says the same thing in signs, notices, and formal writing. Either way, what follows must be the unwanted outcome — if you catch yourself putting the goal there, you want 为了 instead.
Examples
早点出发，免得赶不上火车。
早點出發，免得趕不上火車。
zǎo diǎn chū fā miǎn de gǎn bù shàng huǒ chē
Set off early so you don't miss the train.
多穿点衣服，免得感冒。
多穿點衣服，免得感冒。
duō chuān diǎn yī fu miǎn de gǎn mào
Put on more clothes so you don't catch a cold.
我先给他打个电话，免得他担心。
我先給他打個電話，免得他擔心。
wǒ xiān gěi tā dǎ gè diàn huà miǎn de tā dān xīn
I'll call him first so he doesn't worry.
请把地址写清楚，以免快递送错。
請把地址寫清楚，以免快遞送錯。
qǐng bǎ dì zhǐ xiě qīng chu yǐ miǎn kuài dì sòng cuò
Please write the address clearly to avoid misdelivery.
Common mistakes
✗ 早点出发，免得准时到。
✓ 早点出发，免得迟到。
The clause after 免得 is the bad outcome you're avoiding — for the goal itself, use 为了.
Related grammar points
Practice this pattern in graded stories like Signing the Contract (Part 5), The Sermon on the Mount - Part 3 (Matthew 7) inside the Literate Chinese app.
