zyugyou ga owattara, massugu ie ni kaerimasu.

〜たら is a very common pattern meaning when, after, or if something happens, depending on context.

Here, 授業が終わったら means:

• when class ends
• after class is over

It comes from the past plain form of the verb:

• 終わる = to end
• 終わった = ended
• 終わったら = when/after it ends

Even though 終わった looks past, 〜たら does not necessarily make the whole sentence past. It often means once that event happens, then...

So the structure is:

• A たら、B
• When/after A happens, B

In this sentence:

• 授業が終わったら、まっすぐ家に帰ります。
• When class ends, I go straight home.

In 授業が終わる, 授業 is the thing that ends, so it is marked with が.

• 授業が終わる = class ends

This is because 終わる is an intransitive verb. It describes something ending by itself, rather than someone ending something.

Compare:

• 授業が終わる = class ends
• 先生が授業を終える = the teacher ends the class

So:

• 終わる takes が
• 終える takes を

Why not は? You can sometimes say 授業は終わったら in a different context, but it sounds unnatural here. が is the normal choice because 授業 is simply the subject of 終わる.

These two are related, but they work differently:

• 終わる = to end, to be over
• 終える = to finish something, to bring something to an end

Examples:

• 授業が終わる = the class ends
• 宿題を終える = finish the homework

In your sentence, the class is not being presented as something the speaker actively finishes. It is simply an event that ends, so 終わる is the natural choice.

Both are possible, but they have different levels of politeness.

• 帰る = plain form
• 帰ります = polite form

Since the sentence ends with 帰ります, the whole sentence has a polite tone. This is very common in textbook Japanese and in normal polite conversation.

Notice that the first clause uses the plain form 終わったら, not 終わりましたら. That is normal. In Japanese, subordinate clauses often use plain forms even when the main sentence is polite.

So this combination is completely natural:

• 授業が終わったら、まっすぐ家に帰ります。

Yes, that is completely normal.

Japanese often uses:

• plain form inside a clause
• polite form at the end of the sentence

The politeness of the whole sentence is mainly shown by the final verb.

So in:

• 授業が終わったら、まっすぐ家に帰ります。

the clause 授業が終わったら is just a time condition, and the sentence ends politely with 帰ります.

A very common pattern is:

• 時間があったら、行きます。
• If I have time, I will go.

Not:

• 時間がありましたら、行きます。

That more polite version does exist, but plain forms in subordinate clauses are standard and natural.

Yes, まっすぐ literally means straight, but in this sentence it means something like:

• straight
• directly
• without stopping anywhere else

So:

• まっすぐ家に帰ります。
• I go straight home.

It often implies no detours or no stopping by other places.

For example:

• 学校が終わったら、まっすぐ帰ってきてね。
• When school is over, come straight home, okay?

It does not necessarily mean walking in a physically straight line. It usually means directly in this kind of sentence.

With 帰る, the destination is commonly marked by に or へ.

• 家に帰る = go home
• 家へ帰る = go home

In many cases, に and へ are both possible for destinations.

Here, に is very natural because it marks the destination clearly:

• 家に = to home / homeward destination

So:

• 家に帰ります = I go home

This is one of the most common patterns in Japanese.

Yes, you can say:

• 授業が終わったら、まっすぐ家へ帰ります。

Both are natural, but there is a slight nuance:

• に focuses more on the destination
• へ focuses a bit more on the direction toward that destination

In many everyday sentences, the difference is small, and either one works.

That said, 家に帰る is probably the more common basic expression learners will see first.

Both 家 and うち can mean home, but they are not always identical in feeling.

• 家 is a very basic, neutral word for house/home
• うち often feels a bit more personal, conversational, or like my place / our home

In this sentence, 家に帰ります is a straightforward textbook-style way to say go home.

You may also hear:

• うちに帰る

That is also natural, especially in casual speech.

One more thing: 家 can be read as いえ or うち depending on context, but in 家に帰る, learners are often taught the idea simply as home rather than worrying too much about the reading at first.

Japanese often omits the subject when it is clear from context.

So even though English needs I go straight home, Japanese often just says:

• 授業が終わったら、まっすぐ家に帰ります。

The speaker is understood from the situation.

This is very normal in Japanese. If the speaker said 私は, it would still be grammatical:

• 私は、授業が終わったら、まっすぐ家に帰ります。

But in many contexts, that would sound unnecessary unless you want to emphasize as for me.

It can mean either, depending on context.

授業 basically means class, lesson, or instruction.

In this sentence, it most naturally means:

• when the class ends or
• when classes are over

If someone says this in the middle of a school day, it might mean after this class ends.
If they say it more generally, it could mean after school/classes are finished.

Japanese often leaves that kind of detail to context.

Technically, 〜たら can mean if in some contexts, but here the most natural meaning is when/after.

Why? Because class ending is expected to happen, not a doubtful condition.

So:

• 授業が終わったら、まっすぐ家に帰ります。

is understood as:

• When class is over, I’ll go straight home.

not usually:

• If class ends, I’ll go straight home.

In other words, 〜たら can express either a condition or a time sequence, and this sentence is mainly a time sequence.

Japanese word order is flexible, but not every rearrangement sounds natural.

The most natural order here is:

• 授業が終わったら、まっすぐ家に帰ります。

This puts the time condition first, then the main action.

You could also say:

• 授業が終わったら、家にまっすぐ帰ります。

That is also fine.

But:

• まっすぐ家に、授業が終わったら帰ります

sounds awkward because it interrupts the sentence in an unnatural way.

So yes, Japanese allows some movement, but learners should usually stick to the standard order unless they know the nuance they want.

帰る means to return to the place one belongs, such as:

• home
• one’s country
• one’s hometown
• one’s usual place

So 家に帰ります is literally closer to return home, but in natural English we usually just say go home.

That is why the translation is normally I go straight home, even though the Japanese verb has the nuance of returning to one’s base/home.

Compare:

• 学校に行く = go to school
• 家に帰る = go home / return home

So 帰る is the correct verb for going back home.

Yes, absolutely.

• 授業のあとで、まっすぐ家に帰ります。
• After class, I go straight home.

This is similar in meaning to 授業が終わったら.

The difference is:

• 授業が終わったら emphasizes when class ends / once class ends
• 授業のあとで simply says after class

Both are natural. The 〜たら version feels a bit more event-based: once class ends, then...