Usage patterns
傘をさすto put up/open an umbrella
It started raining, so I put up my umbrella.
傘をたたむto close/fold an umbrella
When I got to the station, I closed my umbrella.
傘を忘れるto forget/leave behind one's umbrella
I left my umbrella on the train.
〈人〉の傘に入るto get under someone's umbrella (share it)
The rain was so bad that I got under my friend's umbrella.
Expressions
乳母日傘bringing up with overprotective care; pampered upbringing; hothouse atmosphere