 English prepositions, in, inside, into, and within, from espressoenglish.net In and inside are often the same. For example, you can say, we are in the house, or we are inside the house. The clothes are in the closet, or the clothes are inside the closet. Both in and inside are correct in these sentences. The word inside implies that the thing is physically enclosed. It is in a container, like 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. For example, I live in Australia. My anniversary is in July. He plays guitar in a band. Into implies movement or transformation. For example, she jumped into the swimming pool. We went into the house. The car crashed into a telephone pole. The caterpillar turned into a butterfly. In all of these sentences, something is moving or being transformed. With some verbs you can use either into or in. For example, he put the card into his pocket, or in his pocket. I threw the paper cup into the trash, or in the trash. She lost her balance and fell into the river, or in the river. Within means inside the limits. These are non-physical limits, like time, distance, or an area of influence. For example, the results will be delivered within 14 days. Most car accidents occur within 5 miles of home. There are many brilliant people within this profession. Because the limits are non-physical, we use within and not inside. We can also use in in these sentences. We also have some expressions using within. Within earshot means at a distance where you can hear something, such as a conversation. Within reason means to the degree that good judgment would allow. Within reach and within one's grasp have two meanings. One is literally able to be taken with your hand, and the other meaning is able to be accomplished. This was a free sample from the new e-book 600 Plus Confusing English Words Explained, available at espressoenglish.net. It has more than 200 pages and over 5 hours of audio to help you understand confusing words and use them correctly.