When learning a language, it's a potentially grave error to say a word in one language means the same as another word in the second language. Many times, the damage will be minimal or negligent. For example, saying that "perro" means "dog" won't hurt you much. But perro doesn't mean dog. Perro means perro and dog means dog. They're pretty much equivalent, but not exactly the same. There are two problems with thinking they are.
You potentially miss out on all the associations that word has. For example, we say it's raining cats and dogs, but in Spanish the idiom is, literally translated, "the sky is falling". Another example is the Russian word for dog. This word has connotations of viciousness and wildness, where in English the word by itself doesn't.
The small words and idiomatic grammar constructions, a.k.a: the glue that holds the language together. We'll look at the preposition "de" in Spanish. De is normally translated as "of" or "for", depending. However, there are times when de is not translated at all. For example, "antes de empezar" (before starting). De can only mean one thing: de. It has it's own uses and meanings in Spanish, which only have mere equivalents in English, if it all in some cases. If you truly want to know and speak a language, you have to get a feel for these small words and understand what they mean in themselves and in relation to the words they're used with, not just what they translate as. Luckily, there's a way to do this that doesn't involve "just getting used to them".
