Examples
Meaning
は marks the topic: what the sentence is mainly about. が marks the subject: the person or thing that exists, acts, or is being identified.
Formation
Put は or が after a noun. For example, 私は means I as the topic, and 犬が means the dog as the subject.
Usage
Use は when introducing a topic or making a general statement about something. Use が when saying that something exists, when identifying which thing it is, or when the subject is new information.
Nuance
は often feels broad and topic-like. It can also create contrast, as in this thing, not another thing. が usually puts focus on the subject itself, so it is common in answers to who or what questions.
Comparison
私は学生です simply says that I am a student. これが私の本です focuses on this as the thing being identified. For existence sentences such as 犬がいます, が is the beginner-friendly default.
Common Mistakes
A common mistake is using は and が as if they were always interchangeable. Another mistake is using は in simple existence sentences where が is more natural, such as saying 犬はいます when you only mean there is a dog.
Related Grammar
を
を (o) marks the direct object of an action verb. It is used when you eat, drink, read, write, watch, or study something.
に
に (ni) points to a specific time, destination, location of existence, or person related to an action. It is one of the most important N5 particles.
で
で (de) marks where an action happens or what means, tool, or language is used. It is different from に, which often marks existence or destination.
も
も (mo) means also or too. It replaces particles such as は, が, or を when adding another person or thing to the same statement.