Learn Hardcore Russian: Моя сестра любит завтракать овсянкой, даже когда ей совсем не хочется есть. - My sister likes to have oatmeal for breakfast even when she doesn’t feel like eating at all.

Моя сестра любит завтракать овсянкой. – She likes to have oatmeal for breakfast.
Моя сестра любит есть овсянку на завтрак. – She likes to eat oatmeal for breakfast.

Both are correct, but завтракать naturally combines with the instrumental.

What is the difference between завтракать овсянкой and есть овсянку на завтрак?

Both mean she eats oatmeal in the morning, but there is a nuance:

завтракать овсянкой – literally to breakfast with oatmeal.
- Focuses on the meal event (breakfast) and what it consists of.
- Sounds very natural and idiomatic.
есть овсянку на завтрак – to eat oatmeal for breakfast.
- Uses the general verb есть.
- Explicitly mentions на завтрак (for breakfast).

So:

завтракать овсянкой = have oatmeal as breakfast
есть овсянку на завтрак = eat oatmeal at breakfast time

In everyday speech, both are fine, but with breakfast/lunch/dinner, Russians often prefer завтракать / обедать / ужинать + instrumental.

Why do we say любит завтракать instead of something like любит завтрак?

In Russian, when you say you like doing something, you very often use:

любить + infinitive (to like to do X)

So:

Она любит завтракать. – She likes to have breakfast.
Она любит завтракать овсянкой. – She likes to have oatmeal for breakfast.

If you say:

Она любит завтрак.

this means she likes breakfast (as a meal / time of day), not she likes having breakfast in general. It sounds more like she loves the occasion of breakfast itself, not the action.

So любить + infinitive is the natural way to say likes to V / likes doing V.

Why is it ей совсем не хочется есть and not она совсем не хочет есть?

Both are grammatically correct, but they feel different:

ей совсем не хочется есть
- Impersonal construction.
- Literally: To her, it completely doesn’t feel like eating.
- Describes an inner state / lack of appetite.
- Neutral, typical way to say she doesn’t feel like eating.
она совсем не хочет есть
- Personal construction with хотеть.
- Literally: She really doesn’t want to eat.
- Can sound more like a conscious refusal, a decision: she does not want to, perhaps is refusing.

In your sentence, the idea is more about her appetite being absent than her consciously deciding not to eat, so ей не хочется есть is more natural.

What exactly does хочется mean, and why does it have -ся?

Хочется is the 3rd-person singular form of хотеться, which is related to хотеть (to want) but used in an impersonal, reflexive way.

хотеть:
- Она хочет есть. – She wants to eat.
- Normal personal verb with a subject.
хотеться (with -ся):
- Ей хочется есть. – She feels like eating / She has a desire to eat.
- Used mostly in impersonal sentences: no grammatical subject like it in English.

The -ся here marks this special, impersonal/reflexive pattern. It expresses a spontaneous feeling or desire rather than a deliberate choice. With ей (dative) it literally means to her, it is being wanted -> she feels like it.

Why is ей used here, and what case is it?

Ей is the dative form of она (she).

The dative often marks the experiencer of a feeling or state with impersonal constructions:

Мне холодно. – I am cold. (Literally: To me, it is cold.)
Тебе скучно. – You are bored. (To you, it is boring.)
Ему грустно. – He is sad. (To him, it is sad.)
Ей хочется есть. – She feels like eating. (To her, it is wanted to eat.)

So ей answers the question кому? (to whom?), and with хочется it means she is the one who experiences this (lack of) desire.

What is the role of совсем in ей совсем не хочется есть?

Совсем is an intensifier.

With negation, it usually means “at all / really / completely not”:

Мне совсем не холодно. – I’m not cold at all.
Он совсем не устал. – He is not tired at all.

So:

ей совсем не хочется есть ≈ she really doesn’t feel like eating at all / she doesn’t feel like eating in the slightest.

Without negation, совсем can mean “completely / entirely”:

Я совсем готов. – I’m completely ready.
Он совсем один. – He is completely alone.

Can we omit есть and just say ей совсем не хочется?

Yes, in many contexts you can:

Ей совсем не хочется.

If it is already clear from context that you are talking about eating, this is natural and common. It then means:

She really doesn’t feel like it (i.e. eating).

Including есть just makes it explicit what she doesn’t feel like doing:

Ей совсем не хочется есть. – She really doesn’t feel like eating.

Both versions are fine; with есть it is more specific.

How would the sentence change if we used позавтракать instead of завтракать?

Завтракать is imperfective (process, habit).
Позавтракать is perfective (completed event).

In your sentence:

Моя сестра любит завтракать овсянкой… – She likes having oatmeal for breakfast (as a general habit).

If you said:

Моя сестра любит позавтракать овсянкой…

this is possible, but it sounds a bit unusual. Любить usually combines with the imperfective infinitive when talking about regular likes/habits.

You would normally use позавтракать for a single completed action:

Сегодня она позавтракала овсянкой. – Today she had oatmeal for breakfast (and finished).

So for a general habit or preference, любить завтракать (imperfective) is the standard choice.

Is the word order ей совсем не хочется есть fixed, or can we change it?

Russian word order is flexible, but not everything sounds natural.

The neutral, most natural order here is:

ей совсем не хочется есть

Some variants are possible for emphasis, but many will sound odd. For example:

Совсем ей не хочется есть. – Focuses on совсем and ей (it is she who really doesn’t feel like eating). Acceptable, but more emotional or contrastive.
Есть ей совсем не хочется. – Strong emphasis on есть (eating is exactly what she doesn’t feel like doing). This can sound dramatic or poetic.

But things like:

ей не хочется совсем есть
совсем не хочется есть ей

tend to sound unnatural or at least marked in everyday speech.

So you can move words a bit for emphasis, but ей совсем не хочется есть is the normal, unmarked order.

Could we say даже когда она совсем не хочет есть instead? Does it sound different?

Yes, you can say:

Моя сестра любит завтракать овсянкой, даже когда она совсем не хочет есть.

This is grammatically correct, but there is a nuance:

ей совсем не хочется есть – focuses on lack of appetite / feeling.
она совсем не хочет есть – can sound more intentional, like she really doesn’t want to eat (she is refusing, or deciding not to).

In many contexts, they may both be translated simply as even when she really doesn’t want to eat, but native speakers feel ей не хочется as softer, more about inner feeling, and она не хочет as more about will/decision.

Why is it моя сестра and not мой сестра?

Russian possessive pronouns agree with the gender (and number, case) of the noun they modify.

The base forms of мой (my) in the nominative are:

мой – masculine (мой брат – my brother)
моя – feminine (моя сестра – my sister)
моё – neuter (моё окно – my window)
мои – plural (мои родители – my parents)

Since сестра (sister) is a feminine noun, you must use the feminine form:

моя сестра, not мой сестра.

Are there similar verbs to завтракать for other meals, and do they also use the instrumental?

Yes, there are corresponding verbs:

обедать – to have lunch
ужинать – to have dinner/supper

They work the same way as завтракать:

обедать чем? – супом (have soup for lunch)
- Мы обедаем супом. – We have soup for lunch.
ужинать чем? – рыбой (have fish for dinner)
- Они ужинают рыбой. – They have fish for dinner.

So all three normally take the instrumental case for what you eat for that meal:
завтракать / обедать / ужинать + [instrumental].