Я обедаю дома.

Russian normally drops the verb “to be” (быть) in the present tense.

• English: I am having lunch at home.
• Russian literal structure: I lunch at home.

The ending -ю in обедаю already shows present tense and 1st person singular (“I”), so Russian doesn’t need a separate word like “am.”

Обедаю comes from обедать, which means “to have lunch / to eat the midday meal.”

Russian has only one present tense, so я обедаю can mean:

• I am having lunch (right now), or
• I (usually) have lunch (habitually), depending on context.

It does not usually mean just “I eat (in general).” For that, Russian uses есть (“to eat”): я ем = “I eat / I am eating.”

The infinitive is обедать (“to have lunch”).

Present-tense conjugation:

• я обедаю – I have lunch
• ты обедаешь – you have lunch (informal, singular)
• он / она / оно обедает – he / she / it has lunch
• мы обедаем – we have lunch
• вы обедаете – you have lunch (formal or plural)
• они обедают – they have lunch

So я обедаю is simply the “I” form of обедать in the present tense.

• ем comes from есть = “to eat” (any food, any meal):

  • Я ем дома. – I eat at home / I’m eating at home.

• обедаю comes from обедать = “to have lunch / eat the midday meal”:

  • Я обедаю дома. – I have lunch at home / I’m having lunch at home.

So обедаю is specifically about lunch (midday meal), whereas ем is generic “eat.”

Both are correct Russian, but they mean slightly different things:

• дома (no preposition) is an adverb meaning “at home.”

  • Я обедаю дома. – I have lunch at home. (general location: at my home)

• в доме literally means “in the house / inside the building.”

  • Я обедаю в доме. – I have lunch in the house (not outside, not in the yard, etc.).

In everyday speech, to say “at home,” Russians almost always use дома, not в доме.

You can, but it sounds more bookish or heavy for everyday speech.

• Я ем обед дома. literally: I eat (the) lunch at home.

More natural options:

• Я обедаю дома. – I have lunch at home.
• Я ем дома. – I eat at home / I’m eating at home.

Using обедать already implies “lunch,” so adding обед as an object is usually unnecessary in casual speech.

Yes.

In Russian, the verb ending shows the person (обедаю = I have lunch), so the subject pronoun Я is often optional in context.

• Я обедаю дома. – neutral, explicit “I.”
• Обедаю дома. – I’m having lunch at home (still clearly “I,” just less formal / more “diary-style” or conversational).

Both are grammatically correct.

Yes, Russian word order is flexible. The basic meaning stays the same, but the emphasis changes:

• Я обедаю дома. – neutral: I have lunch at home.
• Я дома обедаю. – slight emphasis on дома: it’s at home (not elsewhere) that I have lunch.
• Дома я обедаю. – stronger emphasis on “At home” (contrast: maybe at work I don’t): At home, I (do) have lunch.

In isolation, all three are correct; context decides which sounds most natural.

Russian verbs come in imperfective / perfective pairs:

• обедать – imperfective: process, repeated action

  • Я обедаю дома. – I am having lunch at home / I (usually) have lunch at home.

• пообедать – perfective: a completed act of having lunch

  • Я пообедаю дома. – I will have (and finish) lunch at home.
  • Я пообедал дома. – I had (finished) lunch at home.

So обедаю focuses on the action as it’s happening or as a habit; пообедаю / пообедал focuses on completion of the meal.

Stress:

• Я обЕдаю дОма.

Details:

• обедаю – stress on е: обЕдаю [a-BYE-da-yu] (approx.)
• дома (meaning “at home”) – stress on о in the first syllable: ДОма.

Note:
домА (stress on the second syllable) means “houses” (plural), not “at home.”
So дОма = at home; домА = houses.

It can do both; context decides:

• Right now:
  (On the phone) – Где ты? – Я обедаю дома.
  Where are you? – I’m having lunch at home.

• Habit / routine:
  Обычно я обедаю дома. – I usually have lunch at home.

Russian present tense doesn’t distinguish “I eat” vs. “I am eating” formally; the difference is in context or added adverbs like сейчас (now), обычно (usually), часто (often), etc.