Tôi quét rồi lau sàn nhà.

Here rồi links the two actions and shows sequence: first one action happens, then the next.

So Tôi quét rồi lau sàn nhà means something like:

• I swept and then wiped/mopped the floor
• I swept, then cleaned the floor

In this sentence, rồi is best understood as then / and then, not just already.

Because the subject is the same for both actions.

Vietnamese often avoids repeating the subject when it is already clear. So:

• Tôi quét rồi lau sàn nhà

is understood as:

• Tôi quét rồi tôi lau sàn nhà

But the version without the second tôi sounds more natural and less repetitive.

Not necessarily.

Vietnamese verbs do not change form for tense the way English verbs do. So quét and lau do not themselves tell you past, present, or future.

This sentence is often understood as past in context, especially in narration, because it describes completed actions in sequence. But without more context, it could also describe:

• a usual routine
• planned steps
• a general description of what someone does

If you want to make the past clearer, Vietnamese might add words like đã:

• Tôi đã quét rồi lau sàn nhà.

If you want future, you might see sẽ:

• Tôi sẽ quét rồi lau sàn nhà.

They are two different cleaning actions.

• quét = to sweep
• lau = to wipe / clean by wiping / mop, depending on context

So in this sentence:

• quét suggests removing dust or dirt first, usually with a broom
• lau sàn nhà suggests wiping or mopping the floor afterward

In natural English, lau sàn nhà is often best translated as mop the floor, even though the basic meaning of lau is broader than just mop.

Sàn nhà means the floor.

More literally:

• sàn = floor surface
• nhà = house / home

Together, sàn nhà means the floor of a house or room. In many contexts, it is simply translated as floor.

So lau sàn nhà = wipe/mop the floor.

Grammatically, it appears after lau, but semantically it is understood with the whole cleaning sequence.

A learner might expect:

• Tôi quét sàn nhà rồi lau sàn nhà.

This is perfectly clear, but repetitive.

Vietnamese often avoids repeating the same object if it can be understood from context. So:

• Tôi quét rồi lau sàn nhà

naturally suggests:

• I swept the floor and then mopped it

Even though sàn nhà is only said once, listeners understand that the floor is what is being cleaned in both actions.

In other sentences, yes, rồi can mean already. But in this sentence, its most natural role is as a connector showing sequence.

Compare:

• Tôi ăn rồi. = I already ate / I have eaten already.
• Tôi quét rồi lau sàn nhà. = I swept and then mopped the floor.

So the meaning of rồi depends on where it appears and how the sentence is structured.

Yes, but the meaning and flow change a little.

• Tôi quét rồi lau sàn nhà.
  = clearly first sweep, then mop

• Tôi quét lau sàn nhà.
  = awkward or unclear in most contexts

• Tôi quét và lau sàn nhà.
  = I sweep and mop the floor / I swept and mopped the floor

Using và just means and. It links the actions, but it does not emphasize the order as strongly as rồi does.

So if you want to show one action followed by another, rồi is a very natural choice.

Almost, but not exactly.

• và = and
• rồi = then / and then

So:

• Tôi quét và lau sàn nhà = I sweep and mop the floor
• Tôi quét rồi lau sàn nhà = I sweep, then mop the floor

The sentence with rồi makes the order more explicit.

Because Vietnamese verbs do not change form the way English verbs do.

In English:

• sweep → swept
• mop → mopped

In Vietnamese:

• quét stays quét
• lau stays lau

Time is usually shown through:

• context
• time words
• particles such as đã, đang, sẽ
• sentence structure

That is a major difference between English and Vietnamese grammar.

A common way is to add mới:

• Tôi quét rồi mới lau sàn nhà.

This means something like:

• I swept first, and only then did I mop the floor.

The word mới adds a stronger sense of after that / only then.

So:

• rồi = then
• rồi mới = then only afterward / then and only then

Yes, it is natural and understandable.

It sounds like a simple description of doing two cleaning tasks in order. Vietnamese often uses this kind of compact structure:

• subject + verb + rồi
  • verb + object

A speaker could also say more specific versions, such as:

• Tôi quét nhà rồi lau sàn.
• Tôi quét sàn rồi lau sàn nhà.
• Tôi quét xong rồi lau sàn nhà.

But your sentence is normal and natural.

The tones matter a lot:

• Tôi — mid level
• quét — rising, with the sắc tone
• rồi — falling/glottalized contour, with the huyền? No: in standard spelling rồi has the huyền-like grave? Actually it is pronounced with the huyền tone on rồi
• lau — level
• sàn — low falling, huyền
• nhà — low falling, huyền

A useful rhythm is:

• Tôi quét | rồi lau sàn nhà

Try to keep quét rồi lau smooth, since it expresses the sequence of actions.