Grammar JLPT Level N5 - Lesson 1

Structure of は:

Sentence topic + は, Pronounced "わ"

Details about は:

は (pronounced わ) is often considered to be one of the most difficult particles to master in Japanese, alongside が. は marks the topic of the sentence, and describes the whole sentence broadly. However, が primarily marks single actions or statements. We will explore this distinction in more detail when covering が.

田中さんは先生です。
Tanaka-san is a teacher. (Broadly speaking, not compared to anything)
私はトムです。
I am Tom. (Broadly speaking, not compared to anything)

In many sentences (especially short ones), either は or が would be considered perfectly natural.

カレーは辛(から)い。
Curry is spicy. (Broadly speaking, not compared to anything)
私(わたし)は、ワインが嫌(きら)い。
I dislike wine. (Specifically wine)

In the first sentence, は broadly describes what the sentence is about. In the second sentence, は again describes the whole sentence, but が highlights one specific piece of information.

は

Usage Notes for は:

は cannot be used to describe things that you are seeing or experiencing 'in the moment' (right now). This is due to 'in the moment' events being considered part of a larger experience (your whole day for example).

今(いま)はテスト。
I have a test now. (Slightly unnatural, as the test is happening 'right now')
今日(きょう)は、雨(あめ)。
It will rain today. (Natural, as rain is a fairly broad event)

は has 2 main functions. The first marks the topic of the sentence, the second is used for contrast or making comparisons. Although there are no 'strict' rules for this, when は is used toward (or after) the middle of a sentence, it will usually have the nuance of contrast.