Tôi điều chỉnh ống kính.

A natural word-by-word breakdown is:

• Tôi = I
• điều chỉnh = adjust, modify, fine-tune
• ống kính = lens, especially a camera lens

So the sentence structure is very straightforward: I + adjust + lens.

Vietnamese usually follows Subject + Verb + Object, just like basic English.

So:

• Tôi = subject
• điều chỉnh = verb
• ống kính = object

That makes Tôi điều chỉnh ống kính a very direct match to I adjust the lens.

It is best to learn điều chỉnh here as a fixed verb meaning to adjust or to regulate.

Although it is written as two syllables, many Vietnamese words and expressions are made of two parts like this. In this sentence, điều chỉnh functions together as a single verbal idea.

You should not randomly split it and assign a separate English meaning to each part in this sentence. For learners, the safest approach is:

• điều chỉnh = to adjust

Yes, Tôi chỉnh ống kính is also possible and often sounds more conversational.

The difference is roughly:

• điều chỉnh = a bit more formal, complete, or technical
• chỉnh = shorter, more everyday, often used in speech

So both can work, but điều chỉnh may sound slightly more careful or formal.

Yes, literally:

• ống = tube
• kính = glass / lens

But as a full expression, ống kính means lens, especially a camera lens.

So this is a good example of where the literal parts help a little, but the full phrase should be learned as a unit.

Most commonly, ống kính refers to a camera lens.

If you are talking about:

• a camera lens: ống kính is very natural
• eyeglass lenses: Vietnamese often uses other words depending on context
• a contact lens: usually a different expression entirely

So in this sentence, most learners should understand ống kính as camera lens unless context says otherwise.

Vietnamese usually does not use articles the same way English does. There is no mandatory equivalent of the or a/an in many sentences.

So ống kính can mean:

• the lens
• a lens

The exact meaning comes from context.

In an isolated sentence, English often chooses the lens if both speakers already know which lens is being discussed, but Vietnamese does not need a separate word for that.

By itself, ống kính does not clearly mark singular vs. plural. Vietnamese often leaves that to context.

So depending on the situation, it could mean:

• the lens
• a lens
• sometimes even lenses

However, in a simple sentence like this, learners will usually interpret it as singular unless something else suggests plural.

If you want to make plurality clearer, Vietnamese can add words such as những or các in the right context.

Vietnamese verbs do not change form the way English verbs do. điều chỉnh stays the same.

So Tôi điều chỉnh ống kính can mean different times depending on context, such as:

• I adjust the lens
• I am adjusting the lens
• I adjusted the lens

If you want to make time clearer, Vietnamese often adds time or aspect words:

• Tôi đang điều chỉnh ống kính. = I am adjusting the lens.
• Tôi đã điều chỉnh ống kính. = I adjusted / I have adjusted the lens.
• Tôi sẽ điều chỉnh ống kính. = I will adjust the lens.

Yes, sometimes. Vietnamese often drops subjects when they are already understood from context.

For example, in conversation, if it is obvious that I am the one doing the action, a speaker might simply say:

• Đang điều chỉnh ống kính.
• Điều chỉnh ống kính đây.

But if you are learning, it is very good to keep tôi at first, because it makes the sentence clear and complete.

A few key points:

• Tôi has no written tone mark, so it uses the level tone
• điều has the huyền tone, a low falling tone
• chỉnh has the hỏi tone
• ống has the sắc tone
• kính also has the sắc tone

So the tones are:

• Tôi = level
• điều = falling
• chỉnh = dipping
• ống = rising
• kính = rising

Also note:

• đ is not the same as English d in spelling; it is a separate Vietnamese consonant
• ống kính has the ng sound, which English speakers sometimes need practice with
• tone accuracy matters a lot in Vietnamese, so it is worth practicing the whole sentence slowly first

It is understandable, but the most precise wording depends on what kind of adjustment you mean.

• điều chỉnh ống kính = adjust the lens in a general sense
• chỉnh ống kính = a more casual way to say adjust the lens
• chỉnh nét or lấy nét = focus, if you specifically mean bringing the image into focus

So if you literally mean adjusting the physical lens or its settings, Tôi điều chỉnh ống kính works well. If you specifically mean I focus the lens or I focus the camera, another expression may be more exact.

For a negative sentence, add không before the verb:

• Tôi không điều chỉnh ống kính. = I do not adjust the lens / I am not adjusting the lens

To make it a yes-no question, common options include:

• Tôi điều chỉnh ống kính à? = Am I adjusting the lens? / You are adjusting the lens?
• Tôi có điều chỉnh ống kính không? = Am I adjusting the lens? / Do I adjust the lens?

In real conversation, Vietnamese question forms depend a lot on tone and context, but không for negation is one of the most important basics to learn.