In and Inside
In and inside are the same in many cases. You can say:
- We are in the house.
= We are inside the house. - The clothes are in the closet.
= The clothes are inside the closet.
The word inside implies that the thing is physically enclosed – it is in a container (a box, a vehicle, a building with walls, etc.)
This means that when talking about location, time, being included, or other situations where you are not physically surrounded, you should use in, not inside:
- I live in Australia.
- My birthday is in July.
- He plays guitar in a band.
Into
The word into implies movement or transformation:
- She jumped into the swimming pool.
- We went into the house.
- The car crashed into a telephone pole.
- The caterpillar turned into a butterfly.
With the verbs put, throw, drop, and fall, you can use either into or in:
- He put the card into/in his pocket.
- I threw the paper cup into/in the trash.
- She lost her balance and fell into/in the river.
Within
The word within means “inside the limits” – and in this case the limits are non-physical. They can be limits of time or distance, or an area of understanding:
- The results will be delivered within fourteen days.
- Most car accidents occur within five miles of home.
We also have some expressions using within:
- within earshot = at a distance where you are able to hear something (such as a conversation)
- within reason = to the degree that good judgment would allow
- within reach / within one’s grasp = able to be taken with your hand, or able to be accomplished
You can also use within to describe a person’s inner feelings (in this case, you can also use “inside”):
- He tried to hide the anger burning within/inside him.
