xiàyǔ le, wǒmen gǎnjǐn huíjiā ba.

A natural breakdown is:

下雨了 = it has started raining / it’s raining now
我们 = we
赶紧 = quickly, at once, without delay
回家 = go home
吧 = sentence-final particle for a suggestion

So the overall structure is:

[situation] + [what we should do]

In other words: It’s raining, so let’s hurry home.

In Mandarin, 下雨 is the standard way to say to rain.

Literally, 下 often means to fall, and 雨 means rain, so the image is basically rain falling. Mandarin uses similar patterns for weather:

下雨 = rain
下雪 = snow
下冰雹 = hail

Even though English uses rain as a verb by itself, Mandarin usually uses this verb-object style expression.

Here, 了 shows a new situation or change of state.

So 下雨了 does not simply mean rained in the past. It means something more like:

It’s started raining.
It’s raining now.
Oh, it’s raining.

The focus is that the situation has changed, and that change matters now.

No. Mandarin does not have tense in the same way English does.

A very common beginner mistake is to think 了 = past tense, but that is too simple. In this sentence, 了 is better understood as marking a current relevant change:

下雨了 = it wasn’t raining before, but now it is

So this sentence is not mainly about the past. It is about the present situation and the reaction to it.

This is a very useful question, because the two are similar but not identical.

下雨了 usually emphasizes the change of situation:

• 下雨了，我们赶紧回家吧。
• It has started raining, so let’s hurry home.

下了雨 more often treats raining as an event that happened:

• 昨天下了雨。
• It rained yesterday.

So in your sentence, 下雨了 is the natural choice because the speaker notices the rain and reacts to it immediately.

Mandarin often leaves logical connections unstated when they are obvious.

In English, we might say:

• Because it’s raining, let’s hurry home.
• It’s raining, so let’s hurry home.

In Mandarin, it is very normal to just place the two parts next to each other:

下雨了，我们赶紧回家吧。

The cause-and-result relationship is understood from context. This is very common in everyday Chinese.

赶紧 is an adverb meaning:

quickly
right away
without delay
hurry up and...

It adds a feeling of urgency. The speaker is not just saying let’s go home; they are saying let’s go home right now, before it gets worse.

So 我们赶紧回家吧 feels stronger than just 我们回家吧.

Because 赶紧 is an adverb, and in Mandarin adverbs usually come before the verb or verb phrase they modify.

So:

我们赶紧回家 = we quickly go home / let’s hurry home

The order is: subject + adverb + verb phrase

That is why 赶紧 comes before 回家, not after it.

Yes. 赶快 and 赶紧 are very similar, and in many situations they can replace each other.

So you could also say:

下雨了，我们赶快回家吧。

Both sound natural. Very roughly:

• 赶紧 often feels a bit more colloquial and urgent
• 赶快 is also common and natural

For a learner, either one is good.

回家 simply means go home / return home. It is the normal everyday expression.

回到家 emphasizes arriving back home. The 到 adds the idea of reaching the destination.

Compare:

回家吧 = let’s go home
回到家了 = have arrived home

In your sentence, 回家 is the more natural choice because the speaker is talking about what to do next, not emphasizing the final arrival point.

吧 makes the sentence sound like a suggestion, proposal, or gentle urging.

So:

我们赶紧回家吧。 = Let’s hurry home.
This sounds cooperative and natural.

Without 吧, the sentence can sound more direct, more firm, or more like a plain statement.

Sentence-final particles like 吧 are very important in Mandarin because they help show tone and attitude.

Yes, but the feeling changes.

我们赶紧回家吧。
This sounds like a suggestion: Let’s hurry home.

我们赶紧回家。
This sounds firmer and less soft. Depending on context, it can sound like:

• a decision
• a command
• a plain statement

In conversation, 吧 is very natural here because the speaker is proposing an action to the group.

Grammatically, 我们 means we/us. But in this kind of sentence, it often works like English let’s.

So:

我们赶紧回家吧。

is literally we hurry home, okay/suggestively, but the natural English meaning is:

Let’s hurry home.

This is very common in Mandarin: 我们 + verb + 吧 often expresses a suggestion involving both speaker and listener.

The comma separates two closely connected parts:

下雨了
我们赶紧回家吧

It marks a pause between:

1. the situation
2. the response

Chinese often uses commas to join clauses that are logically related, especially in everyday writing. You do not always need a conjunction like because, so, or therefore. The comma is enough.