Аналіз крові підтвердив діагноз.

Because крові is the genitive singular form of кров (blood).

In аналіз крові, the structure is literally analysis of blood, so Ukrainian uses the genitive case after аналіз to show what is being analyzed.

• кров = nominative form
• крові = genitive form

So аналіз крові is the normal way to say blood test or blood analysis.

Діагноз is the direct object of the verb підтвердив, so it is in the accusative case.

However, for many inanimate masculine nouns in Ukrainian, the accusative form is the same as the nominative form. So:

• nominative: діагноз
• accusative: діагноз

That is why the form does not change.

Підтвердив is:

• past tense
• masculine singular
• perfective aspect

It agrees with the subject аналіз, which is a masculine singular noun.

The perfective aspect shows a completed result: the test confirmed the diagnosis.

In the past tense, Ukrainian verbs agree in gender and number with the subject.

Here, the subject is аналіз, which is:

• masculine
• singular

So the verb is підтвердив.

Compare:

• аналіз підтвердив = the analysis confirmed
• процедура підтвердила = the procedure confirmed
• дослідження підтвердило = the study confirmed

No, Ukrainian word order is fairly flexible because case endings show grammatical relationships.

Аналіз крові підтвердив діагноз is a neutral, natural word order:

• subject → verb → object

You could also change the order for emphasis, for example:

• Діагноз підтвердив аналіз крові — puts more focus on діагноз
• Підтвердив діагноз аналіз крові — possible, but more marked and context-dependent

So the original sentence is the most straightforward version.

Ukrainian does not have articles like English a/an and the.

So аналіз крові підтвердив діагноз can mean:

• The blood test confirmed the diagnosis
• A blood test confirmed the diagnosis

Which one is meant depends on context.

Yes. Аналіз крові is a very common and natural expression.

Literally it means analysis of blood, but in real usage it often corresponds to English blood test.

So even though the wording is slightly different from English, it is the standard Ukrainian phrase.

Yes, depending on context.

Ukrainian past tense does not map perfectly onto English tense choices. A perfective past form like підтвердив often means a completed action, so in English it may be translated as:

• confirmed
• has confirmed

The best choice depends on the surrounding context and style of translation.

You know it from both meaning and grammar.

1. Підтвердив is masculine singular, so it agrees with аналіз.
2. Діагноз functions as the thing being confirmed, so it is the object.
3. Semantically, it makes sense that a blood test confirmed a diagnosis, not that a diagnosis confirmed a blood test.

So even without strict word order, the grammar makes the roles clear.

Because Ukrainian often expresses noun + of + noun relationships just by using the genitive case, without a preposition.

So:

• аналіз крові = analysis of blood
• результат тесту = result of the test
• симптоми хвороби = symptoms of the illness

This is a very common pattern in Ukrainian.