Когда папа увидел большой сугроб у гаража, он сказал, что лучше бы мы оставили машину дома.

Папа means dad and is grammatically masculine, even though it has the -а ending that many feminine nouns have.

This is a small group of masculine nouns referring to male people, such as:

• папа — dad
• дядя — uncle
• дедушка — grandpa

So Russian agrees with the meaning, not just the ending:

• папа увидел — dad saw
  not папа увидела

That is why the past tense verb is увидел, the masculine form.

Because увидел is perfective, and it means caught sight of / saw as a completed event.

Russian often uses:

• видеть / видел for ongoing or repeated seeing, or simply having the experience of seeing
• увидеть / увидел for the moment of noticing or seeing something

In this sentence, the idea is that dad saw the snowdrift at a particular moment, and then reacted to it. So увидел fits better.

Compare:

• Когда папа увидел большой сугроб... — when dad saw/noticed a big snowdrift...
• Когда папа видел большой сугроб... — this would sound less natural here, unless you meant something like whenever he saw one, or he was in the process of seeing it

Because Когда папа увидел большой сугроб у гаража is a subordinate time clause: When dad saw the big snowdrift by the garage.

In Russian, subordinate clauses are separated by commas. So the structure is:

• Когда ... , он сказал ...
• When ... , he said ...

The comma marks the boundary between the when clause and the main clause.

It is the direct object of увидел, so it is in the accusative case. But here the accusative looks the same as the nominative.

Why?

Because:

• сугроб is masculine
• it is inanimate
• masculine inanimate nouns usually have the same form in nominative and accusative singular

So:

• nominative: большой сугроб
• accusative: большой сугроб

There is still accusative function, but no visible change in form.

У гаража means by the garage / next to the garage / near the garage.

It is a very common Russian way to express location near something.

• у
  • genitive = by, near, at

So:

• у гаража — by the garage
• у дома — by the house
• у окна — by the window

Compare:

• в гараже = in the garage
• около гаража = near the garage

All are possible in different situations, but у гаража is very natural for something located right by the garage.

Because the preposition у requires the genitive case.

So:

• dictionary form: гараж
• after у: у гаража

This is a normal case pattern in Russian:

• у дома
• у машины
• у гаража

So the ending changes because the preposition controls the case.

Yes, Russian can often omit subject pronouns, especially when the meaning is clear from the verb form. But here он is very natural.

Reasons to include it:

1. Clarity
   After a fairly long opening clause, repeating the subject helps the sentence stay clear.

2. Normal style
   In narration, Russian often uses an explicit pronoun in the main clause after a subordinate clause.

So both are possible:

• Когда папа увидел большой сугроб у гаража, он сказал...
• Когда папа увидел большой сугроб у гаража, сказал...

The first is more natural and clearer for most contexts.

Что introduces a subordinate clause after сказал. Here it means that.

So:

• он сказал, что... = he said that...

This is one of the most common uses of что in Russian.

Structure:

• сказал — said
• что лучше бы мы оставили машину дома — that it would have been better if we had left the car at home

Лучше бы expresses that something would have been better, usually with regret, criticism, or hindsight.

In this sentence:

• лучше бы мы оставили машину дома

means roughly:

• we should have left the car at home
• it would have been better if we had left the car at home

This construction often implies that the action did not happen, and now the speaker thinks another choice would have been better.

It is a very common conversational pattern in Russian.

Because Russian often uses бы + past tense to express unreal, wished-for, or preferable situations.

So лучше бы мы оставили literally looks like better would-be we left, but the natural English meaning is:

• we should have left
• it would have been better if we had left

This is one of those places where Russian grammar does not map directly onto English grammar.

Some common patterns:

• Лучше бы ты позвонил. — You should have called.
• Лучше бы мы остались дома. — We should have stayed home.

So the past tense here does not simply mean ordinary past; it works together with бы to express an unreal or regretted alternative.

Because the sentence is talking about what would have been better in the past, not about a future action and not just the action in general.

Compare:

• лучше бы мы оставили машину дома — we should have left the car at home
• мы оставим машину дома — we will leave the car at home
• лучше оставить машину дома — it is better to leave the car at home

The version in your sentence is specifically about regret or hindsight regarding a completed situation.

Because it is the direct object of оставили.

• оставили что? — машину

The noun машина is feminine, so the accusative singular changes:

• nominative: машина
• accusative: машину

This is a regular feminine singular pattern.

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

Here the idea is:

• leave the car at home

So Russian uses дома, a location word.

Compare:

• оставили машину дома — left the car at home
• поехали домой — went home

A useful shortcut:

• где? where? → дома
• куда? to where? → домой

Yes. That is exactly how Russian expresses this idea.

• оставить = to leave
• машину = the car
• дома = at home

So the Russian phrasing is very close to the English one.

Note that дома here behaves more like an adverb of place than a noun form meaning of the house.

Yes. Russian word order is flexible, although different orders sound more or less natural depending on emphasis.

The given sentence is neutral and natural:

• Когда папа увидел большой сугроб у гаража, он сказал, что лучше бы мы оставили машину дома.

Possible variations include:

• Папа, когда увидел большой сугроб у гаража, сказал, что...
• Увидев большой сугроб у гаража, папа сказал, что...

These versions shift the rhythm or emphasis a little, but the original is probably the most straightforward version for everyday speech or narration.

Not always, but very often it carries one of these tones:

• regret
• mild criticism
• advice after the fact
• frustration

In this sentence, dad is basically saying that bringing the car was a bad idea, probably because the snowdrift makes things difficult.

So it can sound like:

• We should have left the car at home
• It would have been better not to bring the car

Depending on tone of voice, it may sound neutral, annoyed, or slightly reproachful.

Yes. That is also correct, and it is a useful comparison.

• лучше бы мы оставили машину дома
• лучше было бы оставить машину дома

Both mean something like it would have been better to leave the car at home, but they feel slightly different.

The version with мы оставили is more personal and directly points to our action that should have happened.

The infinitive version оставить is a bit more general or detached.

So the original sentence feels more like a real spoken reaction from dad.