Вечером я чувствую усталость.

In the evening I feel tiredness.

Breakdown of Вечером я чувствую усталость.

• я: I
• вечером: in the evening
• чувствовать: to feel
• усталость: the tiredness

Questions & Answers about Вечером я чувствую усталость.

Why does вечером have this -ом ending and no preposition like в?

Вечером is the instrumental case of вечер (evening), used as an adverbial expression of time.

Russian very often uses the instrumental case without a preposition to say “in the X (time of day)”, for common parts of the day:

• утром – in the morning
• днём – in/at the daytime
• вечером – in the evening
• ночью – at night

You normally don’t say в вечером; just вечером is the natural way to express “in the evening” here.

Could I move вечером to another position, like Я вечером чувствую усталость or Я чувствую усталость вечером?

Yes. All of these are grammatically correct:

• Вечером я чувствую усталость.
• Я вечером чувствую усталость.
• Я чувствую усталость вечером.

The basic meaning is the same: “In the evening I feel tiredness.”

Nuance:

• Starting with Вечером slightly emphasizes the time: “As for the evening, that’s when I feel tired.”
• Putting вечером at the end (…усталость вечером) can sound a bit more neutral, like just adding the time detail at the end.

In everyday speech, all three orders are natural.

Why is усталость used instead of the adjective усталый?

Усталость is a noun meaning tiredness / fatigue.
Усталый is an adjective meaning tired.

• Я чувствую усталость. – I feel tiredness (I feel fatigue).
• Я устал. – I am tired (short form adjective; said by a male).
• Я устала. – I am tired (said by a female).

In your sentence, the structure is “I feel [something]”, so Russian uses a noun object:
чувствую (что?) усталость – “feel (what?) tiredness.”

If you want to use the adjective instead, you change the structure:

• Вечером я устал. (m)
• Вечером я устала. (f)

That is “In the evening I am tired”, rather than “I feel tiredness in the evening.”

What case is усталость in, and why does it look the same as the dictionary form?

The dictionary form усталость is feminine singular nominative.

In the sentence я чувствую усталость, the word усталость is in the accusative case as the direct object of чувствую:

• чувствую (что?) усталость – feel (what?) tiredness

For feminine nouns ending in a soft sign (ь), the nominative and accusative singular have the same form:

• Nominative: усталость есть – Tiredness exists.
• Accusative: чувствую усталость – I feel tiredness.

So the form doesn’t change, but the grammatical function is accusative here.

How would I say this sentence in the negative, and does усталость change its case?

Natural negation:

• Вечером я не чувствую усталости.

Here усталость changes to усталости (genitive singular).

In Russian, with negated verbs of possession/feeling, the direct object often goes to the genitive case:

• Я чувствую усталость. – I feel tiredness.
• Я не чувствую усталости. – I do not feel (any) tiredness.

So:

• Affirmative: усталость (accusative)
• Negative: усталости (genitive)

Why is it чувствую, not a form with -ся like чувствуюсь or чувствуюсь усталым?

Чувствовать without -ся takes a direct object:

• чувствовать усталость – to feel tiredness
• чувствовать боль – to feel pain

Чувствовать себя with -ся is used when describing your own state, usually with an adjective:

• чувствовать себя усталым – to feel tired
• чувствовать себя хорошо – to feel well

Your sentence uses the first pattern:
чувствую (что?) усталость – I feel tiredness.

If you wanted the “feel + adjective” pattern, you could say:

• Вечером я чувствую себя усталым. (m) – In the evening I feel tired.
• Вечером я чувствую себя усталой. (f)

Can I just say Вечером я устал instead of Вечером я чувствую усталость?

Yes, and it is very common and often more natural:

• Вечером я устал. (male speaker)
• Вечером я устала. (female speaker)

This is more like “In the evening I am tired” or “By evening I’m tired.”

Difference in nuance:

• Вечером я чувствую усталость. – explicitly mentions the feeling of fatigue; sounds a bit more descriptive or formal.
• Вечером я устал(а). – simple statement of state, very common in everyday speech.

Why is there no word for “a” or “the” before усталость?

Russian does not have articles like “a/an” or “the”. Definiteness and indefiniteness are understood from context, word order, and stress, not from separate words.

So усталость in this sentence can be understood as:

• I feel tiredness,
• I feel (the) fatigue,
• I feel (a feeling of) tiredness.

Russian simply doesn’t mark that distinction with articles.

Is усталость countable? Could it mean “a fatigue” or “a bout of tiredness”?

Усталость is generally used as an uncountable abstract noun, similar to “fatigue” or “tiredness” in English.

You normally don’t say “одна усталость, две усталости” in the everyday sense of “one tiredness, two tirednesses.” It’s usually just a mass concept: “fatigue”, “the state of being tired.”

If you need to talk about episodes, you’d phrase it differently:

• приступ усталости – a wave/bout of tiredness
• чувство усталости – a feeling of tiredness

Is я necessary here, or could you omit the subject pronoun?

You can omit я in many contexts:

• Вечером чувствую усталость.

It is grammatically correct because the verb ending -ю in чувствую already shows 1st person singular.

However, including я is very common and neutral. Omitting it can:

• sound more informal, or
• slightly emphasize the action rather than the person.

Both are fine; Вечером я чувствую усталость is the most neutral, textbook-style version.

What aspect and tense is чувствую, and how would I use a perfective form here?

Чувствую is:

• imperfective aspect
• present tense, 1st person singular of чувствовать

It describes a regular, ongoing, or habitual situation:

• Вечером я чувствую усталость. – In the evenings I (usually) feel tiredness.

The common perfective pair is почувствовать – to feel (at some point, start to feel, notice a feeling):

• Вечером я почувствую усталость. – In the evening I will (at some point) feel tiredness / will start to feel tired.

So чувствую = general/habitual; почувствую = a single, completed moment of feeling in the future.