Let in & lets in letting in let in let in

1. let ...inlinto p.v. When you let people or things in or let people or things into a place, building, room, and so on, you allow them to enter by giving them permission to enter or by opening a door, gate, and so on.

When the guests arrived, the butler opened the door to let them in.

The guard wouldn't let me into the stadium because I had forgotten my ticket.

2. let... inlinto p.v. When an opening, such as a window, door, hole, crack, and so on, allows something to enter, it lets it in.

That small window doesn't let in enough light to read by.

The hole in the screen is letting the mosquitoes into the house.