Tôi trồng cây.

• tôi = I
• trồng = to plant / to grow / to cultivate
• cây = tree / plant

So the sentence is built very simply as I + plant/grow + tree(s)/plant(s).

Because Vietnamese usually uses the same basic word order as English here: Subject + Verb + Object.

• Tôi = subject
• trồng = verb
• cây = object

So it works like I plant trees.

Trồng is used for planting something in the ground and often also growing/cultivating it.

Depending on context, it can be translated as:

• plant
• grow
• cultivate

It is not the same as:

• mọc = to grow/sprout on its own
• lớn lên = to grow up

So Tôi trồng cây suggests that the speaker is actively planting or cultivating plants.

It can mean either, depending on context.

In everyday Vietnamese, cây is a broad word that can refer to:

• a tree
• a plant
• vegetation more generally

So Tôi trồng cây can mean:

• I plant trees
• I grow plants

If you want to be more specific, Vietnamese usually adds another word:

• cây táo = apple tree
• cây hoa = flowering plant / flower plant
• cây cảnh = ornamental plant

Vietnamese does not work like English in this area.

A bare noun like cây often does not show:

• a/an
• the
• singular vs. plural

That information is usually understood from context or added only when needed.

For example:

• Tôi trồng cây = I plant trees / I grow plants / I am planting a tree, depending on context
• Tôi trồng một cái cây = I am planting a tree
• Tôi trồng những cây này = I plant/am planting these trees

So leaving out articles is completely normal in Vietnamese.

Not by itself. Vietnamese verbs usually do not change form for tense.

So Tôi trồng cây is tenseless on the surface. In context, it is often understood as:

• I plant trees
• I grow plants
• sometimes I am planting plants, if the situation makes that clear

If you want to make the time clearer, you can add markers:

• Tôi đang trồng cây. = I am planting/growing plants.
• Tôi đã trồng cây. = I planted / have planted plants.
• Tôi sẽ trồng cây. = I will plant plants.

Not always. Tôi is a common, neutral, fairly safe way to say I, especially in textbooks and polite situations.

But Vietnamese pronouns depend heavily on:

• age
• social relationship
• formality
• family role

In real life, a speaker might use other words instead of tôi, such as:

• em
• anh
• chị
• con
• cháu
• mình

So tôi is correct, but not always the most natural choice in every conversation.

Sometimes, yes.

Vietnamese often drops the subject when it is obvious from context. For example, if people already know who is speaking, you might hear just:

• Trồng cây.

But as a full standalone sentence for learning purposes, Tôi trồng cây is clearer and more complete.

Here, cây is a noun, meaning plant/tree.

That matters because cây can also be a classifier in other sentences.

For example:

• một cây bút = one pen
• một cây xoài = one mango tree

In those examples, cây functions as a classifier. But in Tôi trồng cây, it stands alone after the verb, so it is the noun plant/tree.

A rough learner-friendly guide is:

• tôi: somewhat like toy, but shorter and cleaner
• trồng: one syllable, ending in -ng, with a falling tone
• cây: one syllable with the ây vowel, also ending with a glide like -y

A few important points:

• Vietnamese is tonal, so the tones matter.
• trồng has a marked tone, while tôi and cây have the default level tone.
• The exact sound of tr can vary by dialect.

The best approach is to listen to native audio and repeat the whole phrase as one rhythm: Tôi | trồng | cây

You can add words for time, number, type, or location.

Examples:

• Tôi đang trồng cây. = I am planting/growing plants.
• Tôi trồng cây ở vườn. = I grow plants in the garden.
• Tôi trồng cây ăn quả. = I grow fruit trees.
• Tôi trồng ba cây xoài. = I grow/am planting three mango trees.
• Tôi đang trồng một cái cây. = I am planting a tree.

So the short sentence Tôi trồng cây is natural, but Vietnamese often becomes more precise by adding extra context.