aoi yuuyaku wo erabu.

It is read ゆうやく.

• 釉 = ゆう
• 薬 = やく

釉薬 means glaze in the pottery / ceramics sense, so this is a somewhat specialized word rather than everyday basic vocabulary.

Because 青い is an い-adjective.

In Japanese, い-adjectives modify nouns directly:

• 青い釉薬 = blue glaze
• 大きい皿 = a big plate

Only な-adjectives use な before a noun:

• 静かな部屋 = a quiet room

So 青な釉薬 is incorrect.

を marks the direct object of the verb.

In this sentence:

• 青い釉薬 = the thing being chosen
• を = marks it as the object
• 選ぶ = to choose

So 青い釉薬を選ぶ means choose blue glaze / to choose a blue glaze.

A good way to think of it is:

• What is being chosen? → 青い釉薬

Because Japanese normally uses Subject–Object–Verb word order, and the verb usually comes at the end of the clause.

So this sentence is structured like:

• 青い釉薬 = blue glaze
• を = object marker
• 選ぶ = choose

In natural English order, you would say choose blue glaze, but in Japanese the verb typically comes last.

選ぶ is the dictionary form of the verb.

This form is also called the plain non-past form. Depending on context, it can mean:

• choose
• will choose
• chooses

So 青い釉薬を選ぶ could mean things like:

• to choose blue glaze
• I choose blue glaze
• I’ll choose blue glaze
• someone chooses blue glaze

Japanese often leaves the exact time and subject to context.

The subject is omitted.

Japanese very often leaves out subjects when they are understood from context. So this sentence could mean:

• I choose blue glaze
• We choose blue glaze
• He chooses blue glaze
• Choose blue glaze
• simply to choose blue glaze

without changing the Japanese wording.

That is very normal in Japanese. You do not need to include a subject in every sentence the way you often do in English.

Japanese does not normally use articles like a, an, or the.

So 青い釉薬を選ぶ could mean:

• choose a blue glaze
• choose the blue glaze
• choose blue glaze

The exact meaning depends on context.

This is one of the biggest differences from English: Japanese often leaves definiteness unstated.

Sometimes, yes, but 青い釉薬 is the more straightforward way to say blue glaze.

The difference is roughly:

• 青い釉薬: using the adjective blue
• 青の釉薬: using the noun blue
  • の

For basic color description before a noun, learners should usually start with:

• 青い釉薬
• 赤い花
• 白い皿

You may see 青の〜 in some contexts, but 青い釉薬 is the standard and safest choice here.

Usually it means blue, but like many Japanese color words, its range can sometimes be broader depending on context.

For example, 青 can sometimes cover things that English might call:

• blue
• green-ish shades
• unripe / fresh-looking colors in certain expressions

However, in 青い釉薬, the normal interpretation is simply blue glaze.

In modern Japanese, を is usually pronounced お.

Historically it was associated with wo, which is why it is still romanized as wo in some systems, but in actual speech you will usually hear:

• 青い釉薬を選ぶ
• pronounced roughly as aoi yūyaku o erabu

So when speaking, treat を as o.

No, normal Japanese is usually written without spaces:

• 青い釉薬を選ぶ。

Spaces are often added in teaching materials to make the parts easier for learners to see:

• 青い = adjective
• 釉薬 = noun
• を = particle
• 選ぶ = verb

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