kono mise nara, sukina iro no syatu wo eraberu.

Here, なら gives a sense like if it’s this store, when it comes to this store, or at this store, at least.

So この店なら、好きな色のシャツを選べる means something like:

• If it’s this store, you can choose a shirt in your favorite color(s).
• At this store, you can choose shirts in the colors you like.

It often adds a nuance of contrast, such as:

• maybe other stores don’t have enough variety,
• but this store does.

So なら is not just a plain if; it often means given that it’s this one or as for this one.

この is a determiner, so it must come directly before a noun:

• この店 = this store

Compare:

• これ = this one
• この店 = this store

So:

• これ店 is incorrect
• このの店 is also incorrect

The word この already does the job of modifying 店.

Because 好き behaves like a na-adjective when it directly modifies a noun.

So:

• 好きな色 = a liked/favorite color → more naturally, a color you like

That is why you use な before the noun:

• 好きな色

Not:

• 好きの色 ✘

A useful pattern to remember:

• 好きだ = to be liked / to like
• 好きな + noun = liked / favorite + noun

Examples:

• 好きな食べ物 = favorite food
• 好きな人 = someone you like
• 好きな色 = favorite color / color you like

This is a noun phrase with modifiers stacked in front of シャツ.

Break it down like this:

• 好きな色 = colors you like
• 好きな色のシャツ = shirts of the colors you like

The の links 色 and シャツ.

Literally, it is something like:

• shirts of liked colors

More natural English:

• shirts in the colors you like
• shirts in your favorite colors

So the structure is:

• [好きな 色] の シャツ

The whole chunk modifies シャツ.

The particle の connects nouns. It can show many relationships, not just possession.

Here:

• 色のシャツ literally = shirt(s) of color
• more naturally = shirts in a certain color

So in 好きな色のシャツ, the の is showing a descriptive relationship:

• shirts whose color is one you like

It is not saying the color owns the shirt. It is just linking the idea of color to shirt.

Because シャツ is the thing being chosen.

• シャツを選べる = can choose shirts

The verb 選べる is the potential form of 選ぶ:

• 選ぶ = to choose
• 選べる = can choose

A point learners often notice: with potential expressions in Japanese, you sometimes see が instead of を. But with 選べる, を is very natural and common.

So here:

• 好きな色のシャツを選べる = can choose shirts in the colors you like

Sometimes, yes, Japanese potential forms can take が, but を is very common and natural here.

Compare:

• シャツを選べる
• シャツが選べる

Both can appear in Japanese, but を is especially straightforward when focusing on the action of choosing a shirt.

For a learner, the safest takeaway is:

• in this sentence, を is perfectly natural
• don’t assume potential form always forces が

選べる is the potential form of 選ぶ.

• 選ぶ = choose
• 選べる = can choose

It means basically the same thing as:

• 選ぶことができる = to be able to choose

But 選べる is shorter and more natural in everyday speech.

So:

• 好きな色のシャツを選べる
• 好きな色のシャツを選ぶことができる

Both mean roughly the same thing, but the first is more concise and conversational.

Because この店なら is not simply saying at this store in a neutral location sense. It is using なら to frame this store as the condition/topic.

So it is more like:

• if it’s this store
• when it comes to this store
• as for this store

If you said この店で, that would focus more directly on the location:

• at this store

But この店なら adds the nuance that this store is suitable, exceptional, or preferable in this situation.

It can mean either, depending on context.

• 好きな色 literally means a color you like
• in many cases, natural English may be favorite color

In this sentence, because 色 is not singular in feeling, it may be broader than just one favorite color. It can suggest:

• the colors you like
• your favorite colors

That is why English translations often sound more natural as:

• shirts in the colors you like

rather than forcing favorite color in the singular.

Grammatically, it is choosing the shirt:

• シャツを選べる = can choose a shirt / can choose shirts

But because the shirts are described as 好きな色のシャツ, the sentence implies that you can choose shirts in the colors you like.

So the direct object is shirt, but the important feature of those shirts is their color.

If you wanted to say more directly you can choose the color, you might say something like:

• 好きな色を選べる = you can choose the color you like

The comma just marks a pause and helps readability.

• この店なら好きな色のシャツを選べる
• この店なら、好きな色のシャツを選べる

Both are fine.

The comma makes the sentence easier to process because この店なら is a setup phrase, and then the main statement comes after it.

Japanese puts modifiers before what they modify, so the sentence builds from left to right like this:

• この店なら = if it’s this store / at this store, at least
• 好きな色 = colors you like
• 好きな色のシャツ = shirts in the colors you like
• 好きな色のシャツを = shirts in the colors you like + object marker
• 選べる = can choose

So the core is:

• シャツを選べる = can choose shirts

And everything before シャツ is just narrowing down what kind of shirts they are.