Don’t say: Lucie came in my office and sat down.
Say: Lucie came into my office and sat down.
! In denotes position inside something, while into denotes motion or direction towards the inside of something.
Use in or into in these sentences.
Helen swims ______ the river every summer.
Tom jumped _____ the pool.
They walked ______ the meeting room.
She poured water ______ his glass.
The river flows ______ the sea.
The dogs are playing ______ the garden.
KEY: 1. in, 2. into, 3. into, 4. into, 5. into, 6. in