nǐ de kèběn zài wǒ de zhuōzi shàngmian, nǐ kànjiàn le ma?

Both 的 mark possession.

• 你的课本 = your textbook
• 我的桌子 = my desk/table

In Mandarin, A 的 B often means B belonging to A.

So:

• 你 的 课本 → your textbook
• 我 的 桌子 → my desk

In casual speech, 的 can sometimes be omitted with close relationships or very common combinations, but here keeping 的 is standard and natural.

在 is used to show location: where something is.

The pattern is:

thing + 在 + place

So in this sentence:

• 你的课本 在 我的桌子上面
• Your textbook is on top of my desk

You can think of 在 as meaning something like is at / is in / is on, depending on the location phrase that follows.

Mandarin usually does not use 是 before a location.

English says:

• The textbook is on the desk.

But Mandarin says:

• 课本在桌子上。

Not:

• 课本是桌子上。 ❌

That is because 是 is mainly used to connect nouns, like:

• 我是学生。 = I am a student.

For location, Mandarin normally uses 在, not 是.

Both can mean on, on top of, or above, depending on context.

• 桌子上 = on the table
• 桌子上面 = on top of the table

In many everyday sentences, 上 and 上面 are very similar. 上面 can sound a little more explicit or slightly fuller.

So here:

• 我的桌子上
• 我的桌子上面

are both natural.

Mandarin location statements usually follow this order:

subject + 在 + location

So:

• 你的课本 = subject
• 在 = indicates location
• 我的桌子上面 = location

This word order is very standard in Chinese.

看 means to look or to watch.
看见 means to see or to catch sight of.

So:

• 看 focuses more on the action of looking
• 看见 focuses more on the result: actually seeing something

In this sentence, the speaker is asking whether the other person has actually noticed or seen the textbook, so 看见 is the better choice.

Here 了 marks that the action has been completed or that a new situation has occurred.

So 看见了 means something like:

• saw
• have seen
• did see

It does not always equal English past tense exactly. Instead, it often shows completion or change of state.

In this question, 看见了吗？ asks whether the person has successfully seen/noticed it.

吗 turns a statement into a yes-no question.

Compare:

• 你看见了。 = You saw it.
• 你看见了吗？ = Did you see it? / Have you seen it?

This is one of the most basic question patterns in Mandarin.

Yes, it could be omitted in some contexts, but repeating it is natural and clear.

The full sentence is:

• 你的课本在我的桌子上面，你看见了吗？

The second 你 makes the question direct and easy to follow.

In conversation, people might also say:

• 你的课本在我的桌子上面，看见了吗？

This can sound slightly more casual, but the version with 你 repeated is very normal.

课本 is a noun meaning textbook.

It is made up of:

• 课 = lesson/class
• 本 = root meaning related to books or volumes here

Together, 课本 means textbook or schoolbook.

In this sentence, it is the thing being talked about: the textbook.

Measure words are used with numbers and demonstratives, but not always with plain possession.

For example:

• 一本课本 = one textbook
• 这本课本 = this textbook

But here the sentence just says:

• 你的课本 = your textbook

No number word or demonstrative is being used, so no measure word is needed.

桌子 means table or desk, depending on context.

A useful pronunciation note: the second syllable 子 in many common nouns is often pronounced with a neutral tone.

So:

• 桌子 = zhuōzi
• not usually strong zhuōzǐ

This neutral tone is very common in everyday Mandarin.

Often 面 in 上面 is pronounced lightly, almost like a neutral tone in natural speech: shàngmian.

Learners often first see full pinyin tones in dictionaries, but in real speech some second syllables become lighter. That is normal.

So if you hear:

• shàngmian

that is natural pronunciation.

Common answers include:

• 看见了。 = Yes, I saw it.
• 看见了，谢谢。 = Yes, I saw it, thanks.
• 还没看见。 = I haven’t seen it yet.
• 没看见。 = I didn’t see it.

A very common negative pattern with 看见 is:

• 没看见

not usually 不看见 in this context.

Yes. That would be very natural.

• 你的课本在我的桌子上，你看见了吗？

This is slightly shorter and probably even more common in everyday speech.
Using 上面 is still correct; it just sounds a little more explicit.

It is natural, everyday spoken Mandarin.

It is not especially formal, but it is polite and completely normal. A friend, classmate, teacher, or family member could say it.

If you wanted to sound a little more casual, you might shorten it slightly, for example:

• 你的课本在我桌子上，看见了吗？

But the original sentence is already very standard and clear.