kuukiire wo tukau.

It is read:

くうきいれ を つかう

• 空気入れ（くうきいれ） = air pump / pump for putting air in
• を = object marker
• 使う（つかう） = to use

So the whole sentence is くうきいれをつかう.

空気入れ literally means something like air-putting-in tool.

It is made from:

• 空気（くうき） = air
• 入れ（いれ） = an -er / container / tool / thing for putting in type of noun form from 入れる

In everyday use, 空気入れ usually means an air pump, such as a bicycle pump.

Because here it is being used as part of a noun, not as a full verb.

• 入れる = to put in
• 入れ can be the stem form used inside compound nouns

So:

• 空気を入れる = to put air in
• 空気入れ = a thing used to put air in, an air pump

This kind of noun formation is very common in Japanese.

を marks the direct object of the verb.

Here:

• 空気入れ is the thing being used
• 使う is the verb to use

So 空気入れを使う means to use an air pump.

You can think of it as:

• [object] を [verb]

In this sentence:

• 空気入れ = object
• 使う = verb

使う is the plain dictionary form.

Japanese sentences are often shown in dictionary form when:

• giving vocabulary examples
• showing basic grammar patterns
• writing casual/plain style
• labeling actions in textbooks

Compare:

• 空気入れを使う。 = plain form
• 空気入れを使います。 = polite form

Both are correct. The difference is mainly style and politeness, not core meaning.

Normally, Japanese is written without spaces:

空気入れを使う。

Spaces are often added in beginner materials to make the structure easier to see. They help learners notice:

• where one word ends
• where the particle is
• what the verb is

So the spaced version is for learning convenience, not standard native writing.

Yes. 空気入れ is a general word for a device used to pump air into something.

Depending on context, it could mean a pump for:

• bicycle tires
• balls
• inflatable items

However, in many everyday situations, people will often picture a bicycle pump first unless context suggests something else.

They are related, but they focus on different things.

• 空気入れを使う = use an air pump
• 空気を入れる = put air in / inflate something

So:

• 空気入れを使う talks about the tool
• 空気を入れる talks about the action/result

For example:

• 空気入れを使う。 = Use a pump.
• タイヤに空気を入れる。 = Put air in the tire.

It is grammatically fine, but by itself it can feel a little like a short note, instruction, or action label rather than a full conversational sentence.

That is because Japanese often omits information that is understood from context, such as:

• who is doing it
• what is being inflated
• when or why

So in real context, it could naturally mean things like:

• Use the pump.
• I use a pump.
• Use an air pump for this.

Japanese often relies heavily on context, so short sentences like this are very common.