taion ga sagattara, asita ha kaisya ni ikeru to omoimasu.

が marks 体温 as the thing that changes in the clause 体温が下がったら.

Here, 体温が下がる means body temperature goes down. The temperature is the grammatical subject of 下がる.

If you said 体温は, it would sound more like you were introducing body temperature as a topic for contrast, such as As for body temperature... That is possible in some contexts, but 体温が下がったら is the most natural way to say if my temperature goes down.

Also, Japanese often leaves out the possessor. So 体温 here naturally means my body temperature from context.

下がったら is the past casual form + ら pattern.

• dictionary form: 下がる = to go down, to drop
• past casual: 下がった = went down / dropped
• 下がったら = if it goes down / when it goes down

This 〜たら form is commonly used for if or when, depending on context.

In this sentence, 体温が下がったら means:

• if my temperature goes down, or
• when my temperature goes down

Because the next part talks about a possible future result, English usually translates it as if.

Because 下がる is an intransitive verb, and 下げる is a transitive verb.

• 下がる = something goes down
• 下げる = someone lowers something

So:

• 体温が下がる = body temperature goes down
• 体温を下げる = lower body temperature

In your sentence, the idea is that the speaker’s temperature will drop, not that someone is actively lowering it, so 下がる is the right choice.

明日は makes tomorrow the topic or sets the frame for what follows.

So 明日は会社に行けると思います feels like:

• As for tomorrow, I think I can go to work
• or more naturally, I think I’ll be able to go to work tomorrow

Using は after a time word often gives a slight sense of contrast or emphasis on that time frame. It can imply something like:

• at least tomorrow
• tomorrow, as opposed to today

Without は, 明日 would still be possible, but 明日は sounds very natural here because the speaker is talking specifically about tomorrow’s situation.

There are two separate points here.

1. Why に?

With 行く and 行ける, に marks the destination.

• 会社に行く = go to the company / go to work
• 会社に行ける = can go to the company / can go to work

You may also see へ with movement verbs, but に is very common and natural here.

2. Why 行ける?

行ける is the potential form of 行く.

• 行く = go
• 行ける = can go / be able to go

So the speaker is not simply saying I will go to work tomorrow. They are saying I think I’ll be able to go to work tomorrow, which fits the condition about the temperature going down.

Yes. 行ける is the potential form of 行く.

Formation:

• 行く is a godan verb
• its potential form changes the final u sound to an e sound plus る
• 行く → 行ける

Meaning:

• 行く = to go
• 行ける = can go / be able to go

A subtle point: the potential form can express either:

• ability
• possibility due to circumstances
• permission in some contexts

In this sentence, it is mainly about physical condition / circumstances:

• If my temperature goes down, I think I’ll be able to go to work tomorrow.

The と here marks the content of the thought.

So:

• 行ける = can go
• 行けると思います = I think that I can go

This と is often used before verbs like:

• 思う = think
• 言う = say
• 知っている = know
• 聞く = hear / ask

You can think of it as linking the quoted or reported content to the verb of thinking. It is not the same と as and.

Ending with と思います makes the statement softer and less absolute.

Compare:

• 明日は会社に行けます。
  = I can go to work tomorrow.

• 明日は会社に行けると思います。
  = I think I can go to work tomorrow.

The second one shows uncertainty or caution. That fits this situation well, because the speaker’s ability to go depends on their health.

Japanese often uses と思います to avoid sounding too direct or too certain, especially when talking about predictions, personal judgments, or plans that are not completely fixed.

It can mean either, depending on context.

In general:

• Aたら、B = if A happens, B / when A happens, B

In this sentence, the meaning is conditional:

• If my temperature goes down, I think I’ll be able to go to work tomorrow.

Why if rather than when? Because the speaker does not know whether the temperature will actually go down. It is a possible condition, not a guaranteed future event.

So if is the more natural English interpretation here.

The subject is omitted because Japanese often leaves out things that are clear from context.

Here, the implied subject is almost certainly I:

• (私は) 体温が下がったら、明日は会社に行けると思います。

This sounds natural because:

• 思います usually refers to the speaker’s own thought in this kind of sentence
• the context suggests the speaker is the one with the fever and the one who may go to work

So even though I is not said, it is understood.

Literally, yes, 会社に行く means go to the company.

But in normal English translation, it often becomes go to work, because that is what it means in context.

So:

• literal: go to the company
• natural English: go to work

This is very common in Japanese. Words like 学校に行く, 会社に行く, and 病院に行く are often translated more naturally in English depending on the situation.

Yes, but the nuance would change a little.

体温が下がったら

This sounds very natural for a concrete future condition:

• if/when my temperature goes down

体温が下がれば

This is also possible and means roughly:

• if my temperature goes down

It can sound a little more formal or more like a general condition.

体温が下がるなら

This would mean more like:

• if it’s the case that my temperature will go down
• if my temperature is going to go down

It often depends more on an assumption or prior information.

For this sentence, 下がったら is especially natural because it connects a specific condition to a likely result in everyday speech.

Japanese word order is flexible, but this order is very natural.

The sentence is structured like this:

• 体温が下がったら = if my temperature goes down
• 明日は = as for tomorrow
• 会社に行けると思います = I think I can go to work

A common pattern in Japanese is:

1. condition or background information first
2. main statement later

That helps the listener understand the situation before hearing the conclusion.

You could rearrange some parts, but this version is clear and standard. For example, 明日、体温が下がったら会社に行けると思います would sound less natural if the meaning is specifically if my temperature goes down, then tomorrow I can go. The original order presents the condition first and then the result, which fits the logic well.