Я пройду через парк и быстро доберусь домой.

Пройду is the future tense of the perfective verb пройти.

• идти = to be going / to go on foot in progress
• пройти = to go through, pass, walk a certain distance, complete the action

So:

• Я иду через парк = I am going through the park
• Я пройду через парк = I will go through the park / I’ll walk through the park

In this sentence, the speaker is talking about a completed future action, so perfective пройду makes sense.

Here, пройду через парк means something like:

• I’ll walk through the park
• I’ll go through the park
• I’ll pass through the park

The prefix про- often adds the idea of passing through or covering a route/distance. So it is not just go, but more specifically go through a place.

Через means through or across, and it normally takes the accusative case.

So:

• nominative: парк
• accusative: парк

Because парк is an inanimate masculine noun, its accusative singular is the same as the nominative singular. That is why you see через парк, not a different-looking form.

Other examples:

• через лес = through the forest
• через мост = across the bridge
• через дорогу = across the road

Доберусь comes from добраться, which means to get to, to make one’s way to, or to reach a place, often with a slight sense of effort or successfully arriving.

So быстро доберусь домой means:

• I’ll get home quickly
• I’ll make it home quickly

It is a very natural verb when talking about reaching a destination.

Compare:

• Я быстро дойду домой = I’ll walk home quickly
• Я быстро доберусь домой = I’ll get home quickly / I’ll make my way home quickly

Добраться is often a bit more general than дойти, because it does not focus only on walking.

Because домой means homeward / to home, while дома means at home.

• домой = direction toward home
• дома = location at home

So:

• Я иду домой = I am going home
• Я дома = I am at home

In this sentence, the speaker is moving toward home, so домой is required.

Because Russian often uses separate verbs for separate completed future actions in a sequence.

The sentence structure is:

• Я пройду через парк = I’ll go through the park
• и быстро доберусь домой = and I’ll get home quickly

Both verbs are perfective future, showing actions the speaker expects to complete. This is very natural in Russian.

Russian often omits the subject when it is already clear.

So:

• Я пройду через парк и быстро доберусь домой
• literally: I will go through the park and quickly get home

The second я is unnecessary because the subject is obviously the same person.

You could say Я пройду через парк, и я быстро доберусь домой, but it sounds more repetitive unless you want special emphasis.

Быстро is an adverb meaning quickly, and in Russian adverbs are often placed before the verb they modify.

So:

• быстро доберусь = will quickly get there / get home quickly

Russian word order is fairly flexible, though. You may also hear:

• Я пройду через парк и доберусь домой быстро

But быстро доберусь sounds smooth and natural because the adverb directly introduces how the action will happen.

The first part, пройду через парк, strongly suggests going on foot, because пройти is the verb of motion associated with walking.

The second part, доберусь домой, is more general and simply means reach home / get home.

So the whole sentence most naturally suggests:

• the speaker will go through the park on foot
• and as a result will get home quickly

Yes, but the meaning changes slightly.

• Я пойду через парк = I’ll go via the park / I’ll set off through the park
• Я пройду через парк = I’ll go through the park / I’ll pass through the park

Пойду focuses more on setting off or going, while пройду focuses more on passing through the park as a completed segment of the route.

In this sentence, пройду fits well because the park is being treated as something the speaker will move through on the way home.

Both main verbs are perfective:

• пройду ← пройти
• доберусь ← добраться

Perfective verbs in Russian usually express:

• a completed action
• a single whole event
• a clear result

That is why they work well here: the speaker means they will complete both actions in the future.

If you used imperfective verbs, the sentence would sound different and would focus less on completion. Russian aspect is very important because it tells you not just when something happens, but also how the speaker views the action.