Проектировщик уточнил техническое задание.

Уточнил is the past tense form of the verb уточнить.

The ending -л is the basic marker of the Russian past tense. In the singular, past-tense verbs also show gender:

• уточнил = masculine
• уточнила = feminine
• уточнило = neuter

So уточнил tells us that the subject is masculine singular. That matches проектировщик, which is a masculine noun.

This is a question of aspect, which is very important in Russian.

• уточнить → perfective
• уточнять → imperfective

In the sentence, уточнил is the past tense of the perfective verb уточнить. It usually means the action was seen as completed: the designer clarified / specified / refined the technical brief.

If you used уточнял, that would usually focus more on the process, repetition, or an unfinished action:

• Проектировщик уточнял техническое задание.
  = The designer was clarifying the technical brief / used to clarify it / was in the process of refining it.

So уточнил is used when the clarification is presented as a finished result.

Because it is the direct object of the verb уточнил.

The verb уточнить takes something being clarified, so техническое задание is in the accusative case.

However, here is the important part:
задание is a neuter inanimate noun, and for neuter inanimate nouns, the accusative singular looks exactly like the nominative singular.

So:

• Nominative: техническое задание
• Accusative: техническое задание

They look the same, but the function in the sentence is different.

Because it has to agree with задание.

Russian adjectives agree with the noun in:

• gender
• number
• case

Here, задание is:

• neuter
• singular
• accusative (same form as nominative here)

So the adjective must also be neuter singular in the same case:

• технический → masculine
• техническая → feminine
• техническое → neuter
• технические → plural

That is why the sentence has техническое задание.

Проектировщик usually means a person who designs, plans, or develops technical/project documentation, often in an engineering, architectural, or industrial context.

Depending on context, it can be translated as:

• designer
• planner
• design engineer
• project engineer

It is not always the same as дизайнер, which is often used for visual or artistic design.
Проектировщик usually sounds more technical or engineering-related.

This is a very common technical or business expression in Russian.

Техническое задание often means:

• technical specification
• technical brief
• statement of requirements
• terms of reference

Its exact English translation depends on the industry.

In many contexts, it refers to a document that explains:

• what needs to be done
• what the requirements are
• what technical parameters must be met

So even if the general meaning is already known, it is helpful to understand that this is a fairly standard set phrase in Russian.

Russian has no articles like the or a/an.

So:

• проектировщик can mean the designer or a designer
• техническое задание can mean the technical brief or a technical brief

You understand which one is meant from the context.

In this sentence, English often uses the because the context probably refers to a specific designer and a specific technical brief. But Russian does not need a separate word for that.

Yes. Russian word order is more flexible than English because case endings show grammatical relationships.

The neutral word order here is:

• Проектировщик уточнил техническое задание.

But you could also say:

• Техническое задание уточнил проектировщик.
• Уточнил проектировщик техническое задание.

These alternatives may sound more marked or emphasize different parts of the sentence.

For example:

• Техническое задание уточнил проектировщик can emphasize that it was the designer who clarified it.
• The original order is the most straightforward and neutral.

So changing word order in Russian often changes focus or emphasis, not the core meaning.

The noun and the verb would need to match the new subject.

If the subject were a feminine noun, the verb would usually take the feminine past form:

• Проектировщица уточнила техническое задание.

Here:

• проектировщица = female designer / female design engineer
• уточнила = feminine singular past

So the key change is:

• уточнил → masculine
• уточнила → feminine

A helpful stress pattern is:

• проектиро́вщик
• уточни́л
• техни́ческое зада́ние

So the whole sentence is pronounced approximately as:

проектиро́вщик уточни́л техни́ческое зада́ние

Stress matters in Russian, because it is not always predictable and can affect vowel pronunciation.

All of those can work, depending on context.

Уточнить often means:

• to clarify
• to specify more precisely
• to refine
• to make more exact

In a technical context, clarified the technical specification or refined the technical brief may both be natural translations.

So the core idea is not just explain, but make more precise.