If you've just started learning Japanese, you've met them. They're tiny, they're everywhere, and they're probably confusing you. We're talking about particles: the little words like は (wa), が (ga), を (o), に (ni), and で (de) that seem to float around in every sentence.
In English, we use word order to show who is doing what. "Dog bites man" is very different from "Man bites dog." Japanese uses particles. 犬が人を噛む (Inu ga hito o kamu) means the dog (subject) bites the man (object), no matter where "inu" or "hito" appear in the sentence.
This guide will demystify the most common particles. We won't just list them; we'll tackle the most famous grammar battles head-on, especially は (wa) vs. が (ga) and に (ni) vs. で (de), so you can finally understand their core functions.