は
Topic (wa)
Introduces the main topic of the sentence.
これは本です。
As for this, it is a book.
が
Subject (ga)
Focuses on the specific subject/actor.
雨が降っています。
It is raining. (Focus on 'rain')
を
Direct Object (o)
Marks the direct object of a verb.
水を飲みます。
I drink water.
に
Destination/Time (ni)
Marks target, destination, or specific time.
日本に行きます。
I am going to Japan.
で
Location/Method (de)
Where an action happens or the tool used.
バスで学校へ行きます。
I go to school by bus.
も
Too / Also (mo)
Indicates addition (replaces wa, ga, o).
私も学生です。
I am also a student.