It helps to think of Japanese particles and a sort of glue that bonds the different parts of the sentence together. Each particle has a different meaning and a different way of putting each word in context with the other words.
Here is a very simple sentence that contains a few Japanese particles (particles are in bold):
Did you and your friend eat a hamburger in the restaurant?
Anata to tomodachi wa resutoran de hanbaga o tabemasuka
Here there are five particles used:
wa (は) – This particle follows the subject of the sentences. Think of this particle as a simple marker that says “This is what we are talking about.” In the case of the sentence above, the subject is anata or “you” and tomodachi or “friend.”
to (と) – the particle to is used to essentially mean “and” when it comes between two or more nouns. In the case above, “Anata to tomodachi” uses the particle to to mean “you and your friend.”
de (で) – The Japanese particle de is used to describe where an action happens, or by what means it happens. In the case above, de follows the word resutoran (restaurant), meaning that the action of eating happened in the restaurant.
The particle de can also be used to explain the means by which something happened for example, you might say “watashi wa hashi de gohan o tambemasu” (I eat rice with chopsticks). Here, de is used to show that you used the chopsticks to eat the rice.
o (を) – Simply put, this o article indicates the object that is being effected by a certain verb. In our example sentence, the verb tabemasu (eat) is being done to hanbaga (hamburger). You could also say “hon o yomimasu” (read a book), or “nihongo o benkyoshimasu” (study Japanese). The Japanese particle o indicates what is being read or what is being studied.
ka (か) – This particle is placed at the end of a sentence and it turns the sentence into a question. It is helpful to think of ka as simply the equivalent of a question mark in the English language.
Let’s take another sentence and learn some more Japanese particles:
My friend also goes to the coffee shop.
Watashi no tomodachi mo kissaten ni ikimasu
In this sentence there are three more common Japanese particles used:
no (の) – The particle no is used to indicate possession or relationship to something else. In the above sentence it is used to specify my friend (watashi no tomodachi). It could also be used as in nihongo no gakkusei (Japanese student) or chugoku no resutoran (Chinese restaurant).
mo (も) – The Japanese particle mo can be a little tricky to get the hang of. Mo can replace any other particle and it essentially means “also” or “as well.” In the case of the sentence mo is replacing the particle wa, which changes the sentence from “My friend goes to the coffee shop” to “My friend also goes to the coffee shop.”
ni (に) – The particle ni is used to indicate direction or destination. In our example sentence, our friend is going to the coffee shop, so we use the particle ni. This particle differs from o in that o is used on direct objects (that which is directly effected by the verb), whereas ni is used with indirect objects.
As you can see, learning how to use Japanese particles can be a little confusing at first, but with a little practice you should be able to master them fairly quickly. Again, it’s best not to just memorize which particles go with which verbs, but to instead try to really grasp what the meaning of each particle is and how to use it as a tool to communicate effectively.