Non comprerei quella camicetta neanche se fosse della mia taglia.

Comprerei is the conditional tense of comprare and means I would buy.

So:

• Non compro quella camicetta = I’m not buying that blouse / I don’t buy that blouse
• Non comprerò quella camicetta = I will not buy that blouse
• Non comprerei quella camicetta = I would not buy that blouse

In this sentence, the speaker is talking about a hypothetical situation, not a real action happening now or a definite future decision. The idea is: even under certain conditions, I still wouldn’t buy it.

After se when expressing an unreal, unlikely, or hypothetical condition in Italian, you normally use the imperfect subjunctive in the if-clause and the conditional in the main clause.

So the pattern is:

• se + imperfect subjunctive
• conditional

Here:

• Non comprerei... = I would not buy...
• se fosse... = if it were...

This is the standard pattern for a hypothetical sentence:

• Se avessi tempo, verrei. = If I had time, I would come.
• Se fosse più economica, la comprerei. = If it were cheaper, I would buy it.

Why not the others?

• se è is for a real or possible condition: if it is
• se sarebbe is not standard Italian in this kind of sentence

So se fosse is the correct form here.

Fosse is the imperfect subjunctive of essere.

In this sentence, it comes from essere because the expression is:

• essere della mia taglia = to be my size

A few forms of the imperfect subjunctive of essere are:

• io fossi
• tu fossi
• lui/lei fosse
• noi fossimo
• voi foste
• loro fossero

So se fosse della mia taglia literally means if it were my size.

Neanche means not even or not ... even.

In this sentence:

• Non comprerei quella camicetta neanche se fosse della mia taglia.

the meaning is:

• I wouldn’t buy that blouse even if it were my size.

It adds emphasis. The speaker is saying that being the right size would still not be enough to make them buy it.

You may also see:

• nemmeno
• neppure

These can often mean the same thing as neanche.

Yes, Italian often uses what looks like a double negative to English speakers, but it is completely normal.

Here:

• Non comprerei = I would not buy
• neanche se... = not even if...

So non is negating the verb, and neanche adds the idea of even under that condition, still not.

This is natural Italian, not a mistake.

Quella camicetta means that blouse.

The demonstrative quella points to a specific item, just like that in English. It suggests the speaker is referring to a particular blouse, not blouses in general.

Compare:

• Non comprerei quella camicetta. = I wouldn’t buy that blouse.
• Non comprerei una camicetta così. = I wouldn’t buy a blouse like that.
• Non comprerei la camicetta. = I wouldn’t buy the blouse.

So quella makes it more specific and often more immediate, as if the speaker can see it or has already identified it.

Not exactly.

• camicia usually means shirt
• camicetta usually means blouse

The ending -etta is a diminutive ending, but in modern usage camicetta is simply the normal word for a women’s blouse.

So here quella camicetta is best understood as that blouse.

Literally, della mia taglia means of my size.

Breakdown:

• di = of
• la = the
• della = di + la
• mia = my
• taglia = size

So:

• essere della mia taglia = to be my size / to be in my size / to be the right size for me

In English, we usually say my size rather than of my size, but the Italian structure is very common.

Because Italian normally says essere di una certa taglia or essere della mia taglia when talking about clothing size.

So the structure is:

• essere di + size
• essere della mia taglia = to be my size

Using just la mia taglia after essere would not sound natural here.

For example:

• Questa giacca è della mia taglia. = This jacket is my size.
• Non è della mia taglia. = It’s not my size.

Yes, that is close to the literal structure, but it sounds unnatural in English.

A more natural English translation is:

• I wouldn’t buy that blouse even if it were my size.

That is usually the best way to understand the Italian sentence.

No. It is grammatically more advanced than basic Italian, but it is not especially formal. It is standard, natural Italian.

Italian uses the subjunctive + conditional pattern regularly for hypothetical situations. Native speakers use this structure in everyday speech:

• Se avessi soldi, partirei. = If I had money, I’d leave.
• Se fosse possibile, verrei. = If it were possible, I’d come.

So this sentence sounds normal and idiomatic.

Yes, sometimes the position can vary, but here neanche se is a very natural combination meaning not even if.

For example:

• Non lo farei neanche se me lo chiedessero. = I wouldn’t do it even if they asked me.
• Non andrei neppure se fosse gratis. = I wouldn’t go even if it were free.

In this sentence, neanche se fosse della mia taglia is the clearest and most idiomatic placement.

You usually would not want anche se here if you mean not even if.

• anche se = even if / although, depending on context
• neanche se = not even if

Because the main clause is already negative, neanche se gives the strong meaning: I still wouldn’t buy it under that condition.

So:

• Non comprerei quella camicetta neanche se fosse della mia taglia. = I wouldn’t buy that blouse not even if it were my size.

This is stronger and more precise than using anche se.

The sentence follows a very common Italian pattern for unreal or hypothetical situations:

• main clause in the conditional
• subordinate clause with se + imperfect subjunctive

So:

• Non comprerei = main clause, conditional
• se fosse = if-clause, imperfect subjunctive

Formula:

• (Non) + conditional + ... + se + imperfect subjunctive

Examples:

• La comprerei se costasse meno. = I would buy it if it cost less.
• Non uscirei se piovesse. = I wouldn’t go out if it rained.
• Accetterei se fosse possibile. = I would accept if it were possible.

Your sentence is a strong version of this pattern because it includes neanche, which adds emphasis.

It sounds fairly strong and dismissive. The speaker is saying that the blouse is so unattractive, unsuitable, or undesirable that even one possible advantage — being the right size — would not change their mind.

So the tone is something like:

• firm refusal
• strong lack of interest
• possibly criticism of the blouse’s style, color, or appearance

It is more emphatic than simply saying:

• Non comprerei quella camicetta. = I wouldn’t buy that blouse.

because neanche se fosse della mia taglia adds: not even under that favorable condition.