Myth 10 Some languages have no grammar

Linguistics consider grammar to be a set of rules which is followed when you speak a language. Those rules consist the forms of words that can be made, the way bits of words can be put together, how you put words together to make longer units and rules about the meaning of words.
If a language had no grammar it wouldn’t have prefixes or suffixed, it would have no rules for word order, it wouldn’t have different word classes.
Some people say certain languages have no grammar because there is no grammar book. That has nothing to do with a language having grammar, a grammar book can be written for every language, because every language has their own grammar.

This myth reminds me of a story I've read months ago. There was this exchange student from Russia staying in America. She told people to 'Get in car' and was made fun of by an American for not saying 'Get in the car' to which her reaction was 'Maybe in American you are so stupid that I have to let you know which car I meant, but we are not.' 
It made me think about how in Croatian we don't always use articles, you can say 'get in this/my/his car' but no one does it because in the situation it's clear what you're talking about. 
Every language has their own rules and therefore grammar. The fact that the grammar used in one language is different from yours (sometimes the person might use their grammar rules while translating something) doesn't mean it doesn't exist or that it's bad.