"I am like" = in some situations it means you are sort of doing something, in a pretend fashion or maybe just practising, or doing something not very seriously. "I am like boxing with the children" would mean you are play boxing or shadow boxing with the children, not actually hitting them with your punches, that would harm them. but playing at boxing. It is not a truly grammatical question, it is an idiom/expression. The grammar would be "like" +"boxing" = as though conjunction informal as though; as if. "I felt like I'd been kicked by a camel" Scroll down the page on the link and read the usage notes. https://www.dictionary.com/browse/like Like = as if (conjunction) used in speech for many hundreds of years, some people do not like it. and it is not used in this form in "FORMAL WRITING" but it is spoken and used as in your example "I am like boxing" colloquial idiom/expression.

I am like boxing doesn't really make sense except for some really specific contexts. It means that the speaker has qualities which boxing also has (they are similar in some way). In general "A is like B" means that A shares some traits with B. I like boxing means that the speaker enjoys boxing. Hope this helps.

I like boxing is correct English, but is only true if you do actually like boxing. I do not like boxing, so if I were to say "I like boxing" it would be correct English, but would not be true. Do not confuse true and correct. True means that what you are saying corresponds with reality, correct, in the context of Italki, means that the language used is right. So if someone who does like boxing says "Me likes boxing" it would be true, but not correct.

The first sentence doesn't really make sense as 'like' here is being used to mean 'similar to'. When used to mean this, we can say that 'She is like him in many ways' = She is similar to him in many ways. The second sentence, 'like' is a verb and this sentence makes more sense if you are trying to express hobbies.