nǐ fāshāo le, gǎnjǐn qù yīyuàn ba.

You have a fever; quickly go to the hospital.

Breakdown of nǐ fāshāo le, gǎnjǐn qù yīyuàn ba.

• 你nǐ: you
• 去qù: to go
• 了le: change-of-state particle

Questions & Answers about nǐ fāshāo le, gǎnjǐn qù yīyuàn ba.

What does 了 (le) mean in 你发烧了? Is it the past tense?

Not exactly. In this sentence, 了 does not simply mean past tense.

In 你发烧了, 了 often marks a new situation or change of state:

• before: you were not in the state of having a fever
• now: you are in that state

So 你发烧了 is more like:

• You’ve got a fever
• You have a fever now
• You came down with a fever

Mandarin does not have tense in the same way English does, so 了 is not just a past marker.

Why is there a 吧 (ba) at the end of the sentence?

吧 softens the sentence and makes it sound like a suggestion, recommendation, or gentle urging.

So:

• 去医院。 = Go to the hospital.
  This sounds direct and blunt.
• 去医院吧。 = You’d better go to the hospital / Go to the hospital, okay?
  This sounds more natural and less harsh.

In this sentence, 吧 fits because the speaker is advising the other person.

What does 赶紧 (gǎnjǐn) mean exactly?

赶紧 means quickly, at once, without delay, or hurry and...

It adds a sense of urgency:

• 赶紧去医院吧 = Hurry up and go to the hospital / You should go to the hospital right away

It is commonly used when the speaker feels something should be done immediately.