kakibera wo tukau.

を marks かきべら as the direct object of the verb. In other words, it shows that かきべら is the thing being used.

So the structure is:

• かきべら = the tool/item
• を = object marker
• 使う = to use

A very literal breakdown is use a かきべら.

Japanese sentences often put the verb at the end. This is one of the biggest word-order differences from English.

English often uses:

• I use a scraper.

Japanese often uses:

• [object] を [verb]
• かきべら を 使う。

So even if the English meaning starts with use, Japanese naturally saves the action word for the end.

Japanese often omits the subject when it is already understood from context.

So かきべら を 使う。 could mean:

• I use a かきべら.
• He uses a かきべら.
• We will use a かきべら.

The exact subject depends on the situation. This is very normal in Japanese.

使う is the plain non-past form. In Japanese, the non-past can cover both:

• present / habitual: use / uses
• future: will use

So かきべら を 使う。 could mean:

• (I) use a かきべら.
• (I) will use a かきべら.

Context tells you which one is meant.

Yes. 使う is the plain form, which is often used in:

• casual speech
• dictionary form
• explanations
• notes and instructions
• writing that is not especially polite

The polite version is:

• かきべら を 使います。

That would be a more polite way to say the same thing.

Although it is written を, the particle is pronounced o in modern Japanese.

So this sentence is pronounced roughly like:

• かきべら o つかう

A learner may expect a wo sound because of the written character, but as a particle it is normally just o.

Many tool names, specialized words, and less common nouns are often written in kana instead of kanji, especially in learning materials.

Possible reasons include:

• the kanji is rare or difficult
• the writer wants the sentence to be easier to read
• the word is more commonly seen in kana in some contexts

So seeing かきべら in hiragana is not strange. In Japanese, not every noun has to be written in kanji.

No. In normal Japanese writing, you usually do not use spaces between words.

So this would normally be written as:

• かきべらを使う。

Spaces are often added in textbooks or beginner materials to make the structure easier to see.

In standard Japanese, を is normally expected here because かきべら is the direct object of 使う.

So the standard form is:

• かきべらを使う。

In very casual speech, particles are sometimes dropped, but that is less standard and can sound rough or incomplete to learners. If you are studying basic grammar, it is best to keep を.

Yes, it can be. Japanese allows very short sentences when the context is clear.

かきべら を 使う。 is a complete sentence meaning something like:

• Use a かきべら.
• I use a かきべら.
• We will use a かきべら.

Even though English often wants an explicit subject, Japanese does not always need one.