Definition:
preposition is a word or phrase that shows the relationship between a noun or pronoun and another word. In this case, 'into' is a preposition that expresses direction, creating the phrasal verb 'go into,' which indicates movement towards a certain place or thing. It can also indicate an attributive relationship between two things.
Rules:
when used as a preposition, 'into' implies that something has moved or is moving towards something else without actually reaching it. It is typically used to indicate a change of state, or motion or transformation, such as 'into the future,' 'into a new career,' and 'into two sections.' It can also be used to indicate a change in intensity, or the cause or source of something, such as 'going into debt.'
Examples:
1. The cat leapt into the air, landing on the windowsill.
2. He transformed into a beautiful butterfly.
3. He had gone into debt buying unnecessary luxuries.
Tips:
when used as a preposition, 'into' should be followed by a noun or pronoun; when it is used as an adverb, it should be followed by a verb. It should not be used as a substitute for 'in,' which indicates a static position, not motion or change. In addition, the preposition 'in' should not be used after 'into,' as it is already implied and redundant.