Learn Hardcore Vietnamese: Bếp của Lan rất sạch nhưng vườn của cô ấy bẩn. - Lan's kitchen is very clean but her garden is dirty.

You generally should not say Bếp của Lan là rất sạch in standard written Vietnamese; là is usually used before nouns, not before simple adjectives in sentences like this.

What does của mean, and why does it appear twice?

của is a possessive marker, roughly like “of” or the ’s in English.

Bếp của Lan = “kitchen of Lan” = “Lan’s kitchen”
vườn của cô ấy = “garden of her” = “her garden”

It appears twice because you’re talking about two different possessed things:

Bếp của Lan – the thing owned is bếp.
vườn của cô ấy – the thing owned is vườn.

You could also say:

Bếp của Lan rất sạch nhưng vườn của Lan bẩn.
(“Lan’s kitchen is very clean but Lan’s garden is dirty.”)

Or, if the context is clear, you can shorten and say:

Bếp của Lan rất sạch nhưng vườn bẩn.
(“Lan’s kitchen is very clean but (her) garden is dirty.”)
Here, vườn is understood to be Lan’s from context.

What does cô ấy literally mean, and why use it instead of just Lan again?

Literally:

cô = a term for a young adult woman (also “aunt” or “Miss/teacher” depending on context)
ấy = that (used here as a pronoun marker)

Together cô ấy functions as “she / her” for a young woman.

In vườn của cô ấy, it means “her garden” and refers back to Lan.

Why use cô ấy instead of repeating Lan?

Bếp của Lan rất sạch nhưng vườn của cô ấy bẩn.
Feels natural, avoids repeating the name.

You could also repeat the name:

Bếp của Lan rất sạch nhưng vườn của Lan bẩn.

Or, if the person is speaking directly about themselves:

Bếp của tôi rất sạch nhưng vườn của tôi bẩn.
(“My kitchen is very clean but my garden is dirty.”)

Is cô ấy always used for “she/her”? What about chị ấy, bà ấy, etc.?

Vietnamese third‑person pronouns depend on age and relationship, not just gender.

For a woman, you might see:

cô ấy – “she/her” for a young woman (often younger than the speaker or in a neutral context)
chị ấy – “she/her” for a slightly older young woman (like “older sister”)
bà ấy – “she/her” for an older woman (“grandmother / madam”)
cô ta / chị ta – “that woman (pejorative / distant)” – often negative

In a textbook example with the name Lan, cô ấy is a common neutral choice. In real life, people often just reuse the name or use a kinship term appropriate to age: chị Lan, cô Lan, etc.

How strong is rất? Is it like “very”, “really”, or “so”?

rất is a neutral degree adverb, most similar to “very”.

sạch = clean
rất sạch = very clean

Other common intensifiers:

rất sạch – very clean (neutral)
khá sạch – quite clean / fairly clean
rất là sạch – very clean (more colloquial/emphatic)
siêu sạch – super clean (slangy, informal)

Without rất, the sentence is still natural:

Bếp của Lan sạch nhưng vườn của cô ấy bẩn.
“Lan’s kitchen is clean but her garden is dirty.”

With rất, you’re emphasizing the cleanliness more strongly.

Why is there no word for “the” or “a” before bếp and vườn?

Vietnamese does not have articles like “a/an/the”.

bếp can mean “a kitchen”, “the kitchen”, “kitchen” in general.
vườn can mean “a garden”, “the garden”.

The definiteness is understood from context. In Bếp của Lan, you naturally understand:

Bếp của Lan = “Lan’s kitchen” (the specific one she has)
vườn của cô ấy = “her garden” (again, specific from context)

You can sometimes add classifiers (like cái, ngôi, một cái, etc.) when you really need to stress number or type, but plain bếp, vườn is perfectly normal here.

Could I say “Lan bếp” or “bếp Lan” instead of “bếp của Lan”?

The safe, standard form you should learn first is:

bếp của Lan – “Lan’s kitchen”

In everyday speech, people do sometimes shorten:

bếp Lan – colloquial, like “Lan’s kitchen”

This is common in spoken Vietnamese, especially with close people or well‑known names:

nhà Lan – Lan’s house
phòng Lan – Lan’s room

But bếp của Lan is clearer and more textbook‑correct.
“Lan bếp” is not used to mean “Lan’s kitchen”; that would sound wrong.

What is the difference between bếp, nhà bếp, and phòng bếp?

All relate to “kitchen”, but with nuance:

bếp
Most general; can mean “kitchen” or also “stove/cooking area” depending on context.
nhà bếp
Literally “kitchen house”; often used for “kitchen” as a room/area in a house.
phòng bếp
Literally “kitchen room”; more explicitly “kitchen room”.

In this sentence, Bếp của Lan is natural and commonly used. You could also say:

Nhà bếp của Lan rất sạch nhưng vườn của cô ấy bẩn.
Phòng bếp của Lan rất sạch nhưng vườn của cô ấy bẩn.

All are understandable; bếp alone is very common in speech.

Are sạch and bẩn adjectives or verbs? I see sạch used like an action too.

They are stative words: in English grammar terms, mostly adjectives, but in Vietnamese they can also behave a bit like verbs.

As “adjectives” / states:
- Bếp rất sạch. – The kitchen is very clean.
- Vườn bẩn. – The garden is dirty.
As part of actions:
- Lau sạch bếp. – Wipe the kitchen clean.
- Rửa sạch tay. – Wash (your) hands clean.

So sạch / bẩn can describe:

a state: clean / dirty
a result of an action: make something clean/dirty

In your sentence, they are describing states.

What does nhưng do, and can it go anywhere else in the sentence?

nhưng is a conjunction meaning “but / however”.

The pattern is:

[Clause A] nhưng [Clause B].

Here:

Bếp của Lan rất sạch – Clause A
nhưng – but
vườn của cô ấy bẩn – Clause B

You normally put nhưng at the beginning of the second clause, as in the example.
You can also start a sentence with nhưng in conversation:

Nhưng vườn của cô ấy bẩn.
“But her garden is dirty.”

Putting it in other positions inside the clause is not normal.

Why isn’t there any word like “then” or “as for” (such as thì) before bẩn?

You sometimes see sentences like:

Bếp của Lan thì rất sạch nhưng vườn của cô ấy thì bẩn.

Here thì helps mark contrast more clearly, like “as for” / “on the other hand”.

In your sentence, thì is simply omitted, which is very common:

Bếp của Lan rất sạch nhưng vườn của cô ấy bẩn.

Both versions are grammatically correct. Adding thì makes the contrast a bit more explicit and slightly more formal or emphatic, but it’s not required.

I often hear “rất là sạch”. Is that correct? How is it different from rất sạch?

Both are used, but:

rất sạch – grammatically clean, neutral; good for writing and speech.
rất là sạch – common in informal spoken Vietnamese; adds a casual, emphatic feeling.

So:

Bếp của Lan rất sạch – perfectly standard.
Bếp của Lan rất là sạch – feels more conversational, a bit more expressive.

For learners, stick with rất sạch as your default.

Are there synonyms for bẩn? Does bẩn sound rude or very strong?

Yes, there are synonyms, and bẩn itself is neutral.

bẩn – dirty (neutral, common)
dơ – dirty (more Southern,colloquial)
dơ dáy – filthy, very dirty (stronger/negative)
nhơ bẩn – dirty in a moral/figurative sense (also “filthy” morally)

In this sentence, bẩn is just a normal description:

vườn của cô ấy bẩn. – Her garden is dirty. (not especially rude; just factual)

How do I pronounce the tones in bếp, sạch, vườn, and bẩn?

Very briefly (Northern tones, simplified description):

bếp – sắc tone (´): rising, like the end of an English “What?”
Short vowel ê, ends with -p: bếp (high rising, cut off).
sạch – hỏi tone (ˇ): mid‑fall then rise, like a surprised “uh‑huh?”
Ends with -ch: sặch (a dipping tone).
vườn – huyền tone (`): low falling, like a gentle “yeah.”
vườn is low and slightly falling.
bẩn – nặng tone (.) on ẩ: low, short, and “heavy”, abrupt stop in the throat.
Think of a short, low “bʌn” with a glottal stop at the end.

Mastering the tones takes practice; knowing that each of these words has a different tone is already important for distinguishing them.