1 B2 idiomatic neutral
For something unpleasant, such as bad weather, illness, or a negative condition, to begin and become established.
"The doctors were concerned that infection had set in after the operation."
inseparable
set in
B2 neutral inseparable intransitive
For something unpleasant or difficult to begin and become established.
In plain English
When something bad (like cold weather, infection, or boredom) starts and looks like it will continue for a while.
What does "set in" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B1 neutral
For cold or wet weather to arrive and settle in for a period.
"The rain had set in for the day, so we abandoned our plans for a walk."
inseparable
Usage tip
Almost always used with unpleasant or undesirable subjects: bad weather, disease, decay, despair. Never used for pleasant things beginning. Always intransitive.
Words that pair with "set in"
Natural word combinations native speakers use most often.
winter rot depression infection doubt fatigue
How to conjugate "set in"
The five tense forms you'll use most often.
Base
set in
I/you/we/they
3rd person
sets in
he/she/it
Past simple
set in
yesterday
Past participle
set in
have + pp
-ing form
setting in
continuous
Hear "set in" in the wild
Listen to native speakers using "set in" in real YouTube videos — click a clip to watch it on Looplines.
Other ways to say "set in"
Swap in when you want variety — tap a linked one to explore it.
begin develop establish itself start take hold take root
Keep exploring
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