A inaptidão temporária deixou o doador de sangue inapto.

They come from the same root, but they are different parts of speech:

• inaptidão = a noun: inaptitude, unfitness, disqualification
• inapto = an adjective: unfit, unsuitable, disqualified

So in this sentence:

• A inaptidão temporária = the temporary unfitness/disqualification
• deixou o doador de sangue inapto = made the blood donor unfit/disqualified

A useful way to see it is:

• inaptidão = the condition
• inapto = the person’s resulting state

A is the feminine singular definite article, meaning the.

It is used because inaptidão is a feminine singular noun:

• a inaptidão
• not o inaptidão

In Portuguese, abstract nouns often take an article where English might or might not use one. So A inaptidão temporária is perfectly normal and means The temporary disqualification/unfitness.

Because it agrees with inaptidão, which is feminine.

In Portuguese, adjectives usually agree in gender and number with the noun they describe:

• a inaptidão temporária
• noun: inaptidão = feminine singular
• adjective: temporária = feminine singular

If the noun were masculine, it would change:

• o problema temporário

In Portuguese, adjectives often come after the noun. So:

• inaptidão temporária = temporary disqualification

That is the most neutral and expected order here.

You can sometimes move adjectives before the noun in Portuguese, but that often changes the tone or sounds more literary or emphatic. In this sentence, inaptidão temporária is the normal order.

Literally, deixar often means to leave, but in this structure it means to make someone/something become a certain state.

So here:

• deixou o doador de sangue inapto

means:

• made the blood donor unfit
• left the blood donor disqualified

This is a common Portuguese pattern:

• deixar alguém + adjective

Examples:

• A notícia deixou Maria triste. = The news made Maria sad.
• O acidente deixou o carro inutilizável. = The accident left the car unusable.

So deixou ... inapto is completely normal.

Because doador de sangue is a set expression meaning blood donor.

Literally, it is:

• doador = donor
• de sangue = of blood

Portuguese often uses noun + de + noun where English uses a compound noun:

• doador de sangue = blood donor
• banco de sangue = blood bank
• doação de sangue = blood donation

So o doador de sangue is simply the standard way to say the blood donor.

Because inapto is an adjective, not a noun.

In the structure deixar alguém + adjective, the adjective describes the object:

• deixou o doador de sangue inapto
• made the blood donor unfit

You would not say deixou o doador de sangue o inapto. That would be ungrammatical here.

Compare:

• Ele ficou triste. = He became sad.
• Ela deixou o filho nervoso. = She made her son nervous.

In all of these, the final word is an adjective describing the person.

Not exactly word-for-word, but it expresses a very similar idea.

• inaptidão temporária is a noun phrase: temporary disqualification / temporary unfitness
• temporarily unfit is more like an adjective phrase in English

So the sentence is structured a bit differently from how English might naturally say it. Portuguese is saying something like:

• The temporary disqualification made the blood donor unfit.

In a medical or administrative context, this can sound natural because it talks about the formal status of the donor.

Because Portuguese sometimes uses a noun and then an adjective from the same root in formal or bureaucratic language.

Here, the sentence is saying:

• the temporary disqualification caused the donor to be
• disqualified/unfit

This kind of repetition may sound a bit heavy in English, but it is not unusual in official, legal, or medical Portuguese.

A more stylistically varied sentence could be:

• A inaptidão temporária impediu a doação de sangue.
• O doador ficou temporariamente inapto.

But the original sentence is still understandable and grammatically fine.

Yes, very much so.

Words like inaptidão and inapto are common in formal, medical, legal, and administrative contexts. For example, you might see them in:

• blood donation forms
• medical screening
• official eligibility rules
• HR or legal documents

In everyday casual speech, Brazilians might choose something simpler depending on the context, but for blood donation and screening language, this formal wording is quite plausible.

No. The correct form is inapto, not inapto.

The adjective is:

• masculine singular: inapto
• feminine singular: inapta
• masculine plural: inaptos
• feminine plural: inaptas

So:

• o doador ... inapto
• a doadora ... inapta

The noun is:

• inaptidão

Even though they are related, their forms are different.

Yes. Tornou would also work.

Both deixar alguém + adjective and tornar alguém + adjective can mean to make someone become a certain state.

Compare:

• A inaptidão temporária deixou o doador de sangue inapto.
• A inaptidão temporária tornou o doador de sangue inapto.

The version with deixou is often a bit more common and natural in many contexts. Tornou can sound slightly more formal or more explicitly transformational, but both are grammatical.

Yes, depending on context.

In general, inapto means someone is not fit, not suitable, or not qualified for something. In blood donation language, it often carries the idea of:

• medically unfit
• temporarily ineligible
• disqualified from donating at that moment

So in this sentence, inapto is not just about physical weakness. It is more about official suitability or eligibility.

The structure is:

• A inaptidão temporária = subject
• deixou = verb
• o doador de sangue = direct object
• inapto = object complement / predicative adjective describing the object

So the pattern is:

• [subject] + deixar + [object] + [adjective]

A parallel example would be:

• O exame deixou o paciente preocupado.
• The exam left the patient worried.

In your sentence:

• A inaptidão temporária deixou o doador de sangue inapto.
• The temporary disqualification left the blood donor unfit/ineligible.

That final adjective does not describe the subject; it describes the object.