Осенью бабушка часто готовит тыкву с мёдом, а летом — жареные кабачки с чесноком.

Russian often uses the instrumental case to mean in a certain season.

• осень → осенью = in autumn
• лето → летом = in summer

This is a very common pattern:

• зимой = in winter
• весной = in spring
• летом = in summer
• осенью = in autumn

You can sometimes also use в with seasons in other contexts, but for the general meaning during that season, these instrumental forms are the normal choice.

Both words are direct objects of готовит (cooks/prepares), so they are in the accusative case.

The difference comes from number and noun type:

• тыква is singular feminine

  • nominative: тыква
  • accusative: тыкву

• кабачки is plural inanimate

  • nominative plural: кабачки
  • accusative plural: кабачки

For inanimate plural nouns, the accusative usually looks the same as the nominative. So:

• жареные кабачки = nominative plural
• готовит жареные кабачки = accusative plural, but the form stays the same

The preposition с in the meaning with normally requires the instrumental case.

So:

• мёд → с мёдом
• чеснок → с чесноком

This is a very important pattern:

• чай с лимоном = tea with lemon
• хлеб с маслом = bread with butter
• картошка с грибами = potatoes with mushrooms

So in your sentence:

• тыкву с мёдом = pumpkin with honey
• кабачки с чесноком = zucchini/courgettes with garlic

The adjective жареные must agree with кабачки in gender, number, and case.

Since кабачки is:

• plural
• inanimate
• accusative plural here

the adjective is also plural accusative. For inanimate plural nouns, accusative plural looks like nominative plural, so we get:

• жареные кабачки

Compare:

• nominative: жареные кабачки вкусные
• accusative: я люблю жареные кабачки

The form stays the same because the noun is inanimate plural.

The dash shows that some words are left out because they are understood from the first half of the sentence.

Full version:

• Осенью бабушка часто готовит тыкву с мёдом, а летом бабушка часто готовит жареные кабачки с чесноком.

Russian often avoids repeating words when the meaning is obvious. So after а летом the repeated part is omitted, and the dash marks that omission:

• а летом — жареные кабачки с чесноком

You can understand it as:

• and in summer, she often makes fried zucchini with garlic

А often marks a contrast or comparison, not just simple addition.

Here the sentence contrasts two seasonal habits:

• in autumn → pumpkin with honey
• in summer → fried zucchini with garlic

So а works well because the speaker is setting one season against another.

Very roughly:

• и = and
• а = and/but, with contrast or a switch of topic

In this sentence, а is more natural because the two parts are being compared.

The sentence describes a habitual/repeated action:

• бабушка часто готовит... = Grandma often cooks/prepares...

For repeated, regular, or general actions, Russian normally uses the imperfective.

• готовить = imperfective
• приготовить = perfective

If you used a perfective verb here, it would sound more like a single completed act, which does not fit well with часто (often).

So готовит is exactly what you expect for a routine or habit.

Часто is an adverb meaning often, and in Russian adverb placement is fairly flexible. Putting it before the verb is very natural:

• бабушка часто готовит

This is the neutral word order for saying that she often does this.

Other word orders may be possible for emphasis, but this version sounds standard and smooth.

Yes. Бабушка is the subject of the sentence, and it is in the nominative case.

The basic structure is:

• Осенью = time expression
• бабушка = subject
• часто готовит = predicate
• тыкву с мёдом = object + accompaniment/ingredient

So бабушка answers the question who does the action?

Not always. Готовить can mean several related things, including:

• to cook
• to prepare
• to make

In this sentence, cooks/prepares is the natural meaning because the objects are foods:

• готовит тыкву
• готовит кабачки

So depending on context, you might translate it as cooks, makes, or prepares.

Because the speaker is specifying the preparation method only for the second dish.

• тыкву с мёдом = pumpkin with honey
• жареные кабачки с чесноком = fried zucchini with garlic

Russian does not need to make both halves structurally identical. One side can be more detailed than the other.

If the speaker wanted perfect symmetry, they could add more description to the first half too, but it is not necessary.

Yes. The full version would be something like:

• Осенью бабушка часто готовит тыкву с мёдом, а летом бабушка часто готовит жареные кабачки с чесноком.

Or more naturally, with less repetition:

• Осенью бабушка часто готовит тыкву с мёдом, а летом часто готовит жареные кабачки с чесноком.

The shortened version with the dash is simply more elegant and natural in Russian writing.