HSK 7–9 grammar · conjunction
⋯⋯，以免/免得⋯⋯
⋯⋯，以免/免得⋯⋯ — so as to avoid, lest
Pattern
+
( ) can be left out · other words may come before, between and after
How it works
以免 and 免得 name the unwanted outcome the first action is meant to prevent: "so that … doesn't happen". What follows is the thing to be avoided, so it is never negated — 以免感冒, not 以免不感冒. 免得 is the more colloquial of the two.
Examples
多穿点儿，以免感冒。
Duō chuān diǎnr, yǐmiǎn gǎnmào.
Wear more so you don't catch cold.
早点儿出发，免得堵车。
Zǎo diǎnr chūfā, miǎnde dǔchē.
Set out early to avoid the traffic.
Related
See it in a story
In the app, ⋯⋯，以免/免得⋯⋯ is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.