niwa ni chiisai koya ga aru.

There is a small shed in the garden.

Breakdown of niwa ni chiisai koya ga aru.

• 小ちいさい: small
• が: subject particle
• に: location particle
• ある: to exist/have

Questions & Answers about niwa ni chiisai koya ga aru.

Why is に used after 庭?

に marks the location where something exists.

In this sentence:

• 庭に = in the garden
• 小屋がある = there is a hut

So に is telling you the place in which the hut exists.

A useful pattern is:

• Place に Thing が ある
• Place に Person/Animal が いる

So this sentence follows a very common existence pattern in Japanese.

Why is が used after 小屋?

が marks the thing that exists: the hut.

In 小屋がある, the hut is the thing being identified as existing. So が is very natural here.

Compare:

• 小屋がある = there is a hut
• 小屋はある = as for the hut, it exists / there is a hut, at least

Using が is the neutral, standard choice when you are simply stating that something is there.

Why is the verb ある used instead of いる?

Japanese uses different existence verbs depending on whether the thing is animate or inanimate.

• ある = used for things, objects, places, plants, etc.
• いる = used for people and animals

A hut is an inanimate object, so ある is correct.

Examples:

• 庭に小屋がある。 = There is a hut in the garden.
• 庭に犬がいる。 = There is a dog in the garden.