Cây này có sâu bệnh.

A natural word-by-word breakdown is:

• cây = tree, plant
• này = this
• có = have / has / there is
• sâu bệnh = pests and diseases, or pest/disease problems

So the sentence literally looks like This plant has pests/diseases.

In real use, it often means the plant is affected by pest or disease problems.

In Vietnamese, demonstratives like này usually come after the noun.

So:

• cây này = this plant / this tree
• nhà này = this house
• người này = this person

This is different from English, where this comes before the noun.

Here, có means has.

So:

• Cây này có sâu bệnh = This plant has pest/disease problems.

Vietnamese often uses có in a very broad way to express possession or the presence of something.

Depending on context, có can mean:

• have
• there is / there are
• sometimes more generally contain / possess / show

In this sentence, has is the most natural way to understand it.

It is made of two parts:

• sâu = worms, insects, pests
• bệnh = disease

Together, sâu bệnh is a common agricultural expression meaning pests and diseases or pest/disease damage.

So even though it is built from two words, learners should treat it as a common fixed combination.

It can mean either, depending on context.

• In some situations, cây means tree
• In others, it means plant

In a sentence about agriculture, gardening, or crop health, plant is often the safer broad translation unless the context clearly points to an actual tree.

So Cây này có sâu bệnh could mean:

• This plant has pests/diseases.
• This tree has pests/diseases.

Vietnamese does not always need a verb like English is.

This sentence is not saying This plant is pest-ridden with a linking verb. Instead, it uses có = has.

So the structure is:

• cây này = this plant
• có = has
• sâu bệnh = pests/disease problems

Vietnamese often expresses ideas more directly and does not always match English word-for-word.

Yes, you can.

• Cây này có sâu bệnh
• Cái cây này có sâu bệnh

Both are understandable.

The version without cái is very common and natural.
Adding cái can make the noun phrase feel a little fuller or more specific, like this plant/tree here.

However, with many plant names and in general statements, people often simply say cây này.

Yes, Cây này bị sâu bệnh is also natural.

The difference is roughly:

• có sâu bệnh = has pest/disease problems
• bị sâu bệnh = is affected by pests/disease; suffers from pest/disease problems

So bị emphasizes being negatively affected.

Compare:

• Cây này có sâu bệnh = This plant has pests/diseases.
• Cây này bị sâu bệnh = This plant is suffering from pests/diseases.

Both are common, but bị sounds a bit more explicitly negative.

A rough guide:

• sâu: sounds somewhat like sow in English, but with Vietnamese pronunciation and the ngang level tone
• bệnh: roughly like benh with a nặng heavy/falling-glottal tone

A few pronunciation notes:

• âu in sâu is not exactly an English vowel, so it is best learned by listening.
• ệ/ệnh in bệnh also does not match English exactly.
• The final nh in bệnh is a real Vietnamese ending sound, not a separate syllable.

If your tones are still developing, focus first on saying the right syllables clearly, then improve the tones with listening practice.

Historically and literally, sâu can mean worm or caterpillar-like pest, but in farming and gardening language it often refers more broadly to pests.

So in sâu bệnh, it is usually better not to translate it too narrowly as only worms.
The whole phrase is broader and more idiomatic than that.

Usually it is a general statement.

Vietnamese nouns often do not mark singular vs. plural the way English does. So sâu bệnh can mean:

• pest problems
• disease problems
• pests and diseases in general

The exact number is usually not important unless the speaker adds more detail.

Yes. It is short, natural, and easy to understand, especially in contexts like:

• farming
• gardening
• plant care
• crop inspection

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

• Cây này có sâu = This plant has pests.
• Cây này bị bệnh = This plant is diseased.
• Cây này bị sâu ăn lá = This plant has insects eating its leaves.

But Cây này có sâu bệnh is a very normal general sentence.

Normally no, not in this form.

Sâu bệnh is mainly used for:

• plants
• crops
• agriculture
• farming contexts

For people, you would usually just say bệnh for illness, not sâu bệnh.

So this expression is strongly associated with plant health and agricultural problems.