So as to avoid / lest (免得 / 以免)

Structure Action，免得 / 以免 + the bad thing avoided

免得 (miǎnde) and 以免 (yǐmiǎn) introduce what you want to AVOID: "so as not to…, lest…". 多穿点，免得感冒 = "dress warmly so you don’t catch a cold"; 请提前通知，以免大家白跑一趟 = "give notice in advance so nobody makes the trip for nothing". They go in the second clause, before the bad outcome. 以免 is a bit more formal than 免得.

Examples

多duō穿chuān点diǎn，免miǎn得de感gǎn冒mào。
Dress warmly so you don’t catch a cold.
早zǎo点diǎn出chū发fā，免miǎn得de迟chí到dào。
Leave early so you’re not late.
请qǐng提tí前qián通tōng知zhī，以yǐ免miǎn大dà家jiā白bái跑pǎo一yī趟tàng。
Give notice in advance so nobody makes the trip for nothing.

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.