Grammar · Particles
は, the topic marker
The pattern
[Topic] は [comment]
[Topic] wa [comment]
は marks what the sentence is about, and it is said 'wa', never 'ha'. English has no equivalent, so think of it as 'as for'. Everything after は is the comment on that topic.
The mistake to avoid
It is not the subject marker. That is が, and the difference is the single hardest thing at this level. See the next two entries.
Examples
Rōmaji help
私は学生です。
わたしは がくせいです。
watashi wa gakusei desu.
I am a student.
これは水です。
これは みずです。
kore wa mizu desu.
This is water.
田中さんは先生です。
たなかさんは せんせいです。
tanaka-san wa sensei desu.
Mr Tanaka is a teacher.
今日は暑いです。
きょうは あついです。
kyō wa atsui desu.
It is hot today.