На день рождения бабушка принесёт свечи, а папа пообещал купить шарики.

На день рождения is a very common Russian expression meaning for the birthday or for the birthday celebration.

Here is the case breakdown:

• на often takes the accusative when it means movement toward an event, purpose, or destination.
• день is in the accusative singular. For an inanimate masculine noun like день, the accusative looks the same as the nominative: день.
• рождения stays in the genitive singular because день рождения is a fixed phrase meaning birthday literally day of birth.

So:

• день = accusative
• рождения = genitive

This whole phrase is idiomatic, so it is best to learn на день рождения as a chunk.

Because день рождения literally means day of birth.

In Russian, when one noun describes another in a relationship like day of X, the second noun is usually put in the genitive:

• день = day
• рождение = birth
• день рождения = day of birth

That is why you get рождения, the genitive singular form of рождение.

Russian has no articles like a, an, or the.

So:

• бабушка can mean grandmother, the grandmother, or a grandmother
• папа can mean dad, the dad, or just dad

The exact meaning depends on context. In this sentence, English would naturally say Grandma and Dad because the context makes it clear who they are.

Бабушка is the subject of the verb принесёт, so it stays in the nominative case.

The phrase На день рождения is just an introductory phrase meaning for the birthday. It does not control the case of бабушка.

Structure:

• На день рождения = prepositional phrase
• бабушка = subject
• принесёт = verb
• свечи = object

So бабушка stays nominative because she is the one doing the action.

Because some Russian masculine nouns, especially words for male people, end in -а or -я and decline like feminine nouns in some forms.

Папа is one of them. It is grammatically masculine, even though its ending looks feminine.

Examples:

• папа пришёл = Dad arrived
  
  • пришёл is masculine past tense, which shows that папа is masculine
• дядя сказал
• мужчина вошёл

So the ending does not always tell you the gender.

Принесёт means will bring. It is the simple future of the perfective verb принести.

This is used because the bringing has not happened yet. It is something Grandma will do for the birthday.

Russian forms the future in two main ways:

1. Imperfective future: будет + infinitive

   • будет приносить = will be bringing / will bring repeatedly

2. Perfective future: one simple form

   • принесёт = will bring

Here, принесёт is perfective, so it presents the action as a single completed event: she will bring the candles.

This is an aspect and prefix question.

• нести = to carry, to be carrying
• принести = to bring, to carry something and arrive with it

The prefix при- often adds the idea of arrival or bringing something to a destination.

So:

• нести focuses on the carrying process
• принести focuses on successfully bringing something

In this sentence, Grandma is not just carrying candles somewhere in general; she is bringing them for the birthday. So принесёт is the natural choice.

Свечи is the accusative plural of свеча because it is the direct object of принесёт.

• singular: свеча = candle
• plural nominative: свечи = candles
• plural accusative for inanimate nouns: also свечи

Since candles are inanimate, the plural accusative looks the same as the plural nominative.

So:

• бабушка принесёт что? → свечи

Шарики is also accusative plural, because it is the direct object of купить.

• singular: шарик
• plural nominative: шарики
• plural accusative for inanimate nouns: шарики

Again, because шарики are inanimate, nominative plural and accusative plural are the same.

In context, шарики usually means balloons or sometimes little balls, depending on the situation. In a birthday sentence like this, it clearly means balloons.

Because the sentence is talking about a promise, not just a future action.

• пообещал = promised
• купить = to buy

So папа пообещал купить шарики means Dad promised to buy balloons.

This is different from:

• папа купит шарики = Dad will buy balloons

The Russian sentence tells us about Dad's earlier act of promising. The buying itself is still in the future relative to that promise.

Because the past tense refers to the act of promising, not to the act of buying.

So the timeline is:

1. Dad promised earlier.
2. The actual buying will happen later.

That is why Russian uses:

• пообещал = he promised
• купить = to buy

English works the same way:

• Dad promised to buy balloons

The promise is in the past; the buying is still future from that past point.

After verbs like пообещать (to promise), Russian often uses the infinitive to express the action that was promised.

So:

• пообещал купить = promised to buy
• пообещал принести = promised to bring
• пообещал помочь = promised to help

This is very similar to English promised to buy.

А often links two parts of a sentence by contrasting or comparing them, even when both are positive.

Here it has the sense of:

• Grandma will bring candles, while Dad promised to buy balloons

It is not a strong contradiction like but in every context, but it does set the two people and their roles side by side.

Compare:

• и = and, simple addition
• а = and/while/but, with contrast or comparison
• но = but, stronger contradiction

So а is natural because the sentence contrasts what Grandma will do with what Dad promised to do.

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

This sentence uses a very natural order:

• На день рождения = sets the occasion first
• бабушка = introduces the subject
• принесёт = verb
• свечи = object

But other orders are possible, with different emphasis:

• Бабушка принесёт свечи на день рождения
  More neutral in some contexts.
• Свечи бабушка принесёт на день рождения
  Emphasizes candles.
• На день рождения свечи принесёт бабушка
  Emphasizes that Grandma is the one who will bring them.

So the chosen word order sounds natural and informative, with the birthday context first.

Usually, yes, in ordinary family context that is how English would understand it: Grandma and Dad.

Russian often omits possessive words like my when the relationship is obvious from context.

So:

• бабушка may imply my grandmother / our grandmother
• папа may imply my dad / our dad

If Russian wants to be explicit, it can say:

• моя бабушка
• мой папа

But in everyday speech, that is often unnecessary.

In this sentence, yes, that is the most natural meaning.

Literally, шарик can mean:

• a small ball
• a balloon, especially in everyday speech

Because the context is a birthday, шарики is understood as balloons.

If someone wanted to be more explicit, they might say:

• воздушные шарики = balloons, air balloons

But just шарики is very common in this context.

Literally, yes, свечи just means candles.

But in the context of На день рождения, the natural interpretation is birthday candles, the kind put on a cake.

Russian often relies on context instead of adding extra words. So even without saying свечи для торта, the meaning is clear.