A first overview

And in order to escape the awkward situation of having only a single post, here is a little overview of the Japanese language, especially grammar, in general:

First of all, English and Japanese really differ a lot: While it's usually easy to tell what an English sentence expresses, the meaning of a Japanese phrase depends so much on the context that it can be hard or even impossible to understand it without knowing who said it to whom in which situation.
As an example of this, the following Japanese verb: "wakaru" ( 分かる) 
It has several meanings, all of which have their own word in English: It can for example mean "to know", "to understand" (a language, a statement ...) and many others, all depending on the context.

The second big difference is that, while in English the form and position in the sentence of a word mark its role, in Japanese there are small markers for this task that are placed behind the parts of a sentence, also called "particles".
The most common particles are "wa" and "o", but there are many others.
Consider the following sentence: "Watashi wa prezento o kaimasu", which translates to "I'm buying a present".
When trying to literally translate it, it would look something like this: "I [the actor of the sentence] present [the subject] buy".
The Information in the brackets is in this case transmitted trough the particles.

If you want to read more about those topics, try checking out the following sites:

Particles
Japanese Word order