kare ni wa ishiki ga arimasu.

He is conscious.

Breakdown of kare ni wa ishiki ga arimasu.

• は: topic particle
• が: subject particle
• に: indirect object particle
• 彼かれ: he

Questions & Answers about kare ni wa ishiki ga arimasu.

Why is 彼 followed by には instead of just は?

には is に + は.

Here, に marks the person or thing that has something in a more formal or abstract pattern:

• N に は X がある
• literally: As for N, there is X

So 彼には意識があります is structurally like As for him, consciousness exists.

The は adds topic or contrast. It often gives a nuance like:

• as for him
• he, at least
• in his case

If you said 彼は意識があります, it would sound unnatural in standard Japanese.

What exactly does に do in this sentence?

In this pattern, に marks the location/existence target for what is possessed.

Japanese often expresses to have as something exists with/for someone rather than using a direct verb meaning have.

So:

• 彼に意識がある
• literally: Consciousness exists in/with him

This is why に is used instead of something like a direct object marker.

Why is 意識 marked with が?