sihatu ni noreba, kuukou ni hayaku tukimasu.

始発 means the first departure of the day. In many contexts, English speakers naturally translate it as the first train, but it can also refer to the first bus, subway, etc., depending on the situation.

So 始発に乗る means to take the first train/first departure.

The verb 乗る means to ride or to get on, and the thing you ride is usually marked with に.

• 電車に乗る = ride the train
• バスに乗る = ride the bus
• 始発に乗る = take the first train / get on the first departure

So here, に marks what you are getting on.

乗れば is the conditional -ば form of 乗る.

• Dictionary form: 乗る
• Conditional form: 乗れば

It means if you ride/get on or if you take.

So:

• 始発に乗れば = if you take the first train

This -ば form often sounds a little logical or matter-of-fact, like stating a condition and its result.

Both can mean if you take in a sentence like this, but the nuance is a little different.

• 乗れば: more like a logical condition
• 乗ったら: often feels more conversational and can also suggest when/after

In this sentence:

• 始発に乗れば、空港に早く着きます。
• 始発に乗ったら、空港に早く着きます。

Both are natural, but 乗れば sounds slightly more like If you do X, then Y will happen.

The comma separates the if-clause from the main clause:

• 始発に乗れば、 = if you take the first train,
• 空港に早く着きます。 = you’ll arrive at the airport early.

Japanese commas are often used more flexibly than English commas, so the comma here helps readability and gives a natural pause, but it is not always absolutely required.

Here, に marks the destination of the verb 着く.

• 空港に着く = arrive at the airport
• 学校に着く = arrive at school

So the two に particles are doing different jobs:

• 始発に乗る: marks what you get on
• 空港に着く: marks where you arrive

早い is an i-adjective, and when an i-adjective modifies a verb, it changes to its adverb form:

• 早い → 早く

Here, 早く modifies 着きます:

• 早く着きます = arrive early

So this is the same kind of change as:

• 速い → 速く
• 新しい → 新しく

In this sentence, it means early or earlier, not really quickly.

That is because the context is about when you arrive at the airport, not the speed of movement itself.

So:

• 空港に早く着きます = you’ll arrive at the airport early / earlier

Even though 早く can sometimes be translated as quickly, context is what tells you which meaning is intended.

Japanese non-past forms often cover both:

• present/habitual meaning
• future meaning

So 着きます here means will arrive.

In conditional sentences, this is completely normal:

• 始発に乗れば、空港に早く着きます。
• If you take the first train, you will arrive at the airport early.

Japanese does not need a separate future tense the way English often does.

Japanese very often leaves out the subject when it is clear from context.

So this sentence could mean:

• If you take the first train, you’ll arrive at the airport early
• If we take the first train, we’ll arrive at the airport early
• If one takes the first train, one arrives early at the airport

In most real situations, the listener understands who is being talked about, so Japanese does not need to say the subject explicitly.

It can be understood as either, depending on context.

Grammatically, it states a condition and result:

• If you take the first train, you’ll arrive at the airport early.

But in real conversation, that often functions as advice or a suggestion:

• You want to get there early? Take the first train.

So the sentence itself is neutral, but the context may make it feel like helpful advice.

Yes. 始発 literally means the first departure/service, so it is not limited to trains.

Depending on context, it could refer to:

• the first train
• the first subway
• the first bus

However, in many textbook-style sentences, learners often understand it as the first train unless the context says otherwise.