wǒ bǎ zīliào fàng zài sùshè le, xiàwǔ shàngkè de shíhou yào yòng.

把 marks the object 资料 and brings it in front of the verb. This is called the 把-construction.

Basic idea:

• normal order: 我放资料在宿舍了
• 把 order: 我把资料放在宿舍了

The 把 pattern is often used when:

• the object is specific and known
• the speaker does something to that object
• the sentence tells us the result, location, or change involving that object

So 我把资料放在宿舍了 means something like:

• I put the materials in the dorm
• I left the materials in the dorm

The focus is on what happened to 资料: it ended up 在宿舍.

That happens because of 把.

In English, we usually say:

• I put the materials in the dorm.

In Chinese, with 把, the structure is roughly:

• subject + 把 + object + verb + result/location/etc.

So here:

• 我 = subject
• 把资料 = take the materials as the object being handled
• 放在宿舍 = put them in the dorm
• 了 = marks the action as completed / a new situation

This structure emphasizes the handling and final placement of the object.

In this sentence, 了 shows that the action has been completed or that a new situation now exists.

So:

• 我把资料放在宿舍了

means the materials are now in the dorm because the speaker already put them there.

This 了 is not exactly the same as the English past tense, although it often overlaps with past meaning. It is better to think of it as marking:

• completion of an action, or
• a changed state

Here it suggests:

• I’ve put / left the materials in the dorm
• and now that is the current situation

Here 在 introduces the location.

• 放在宿舍 = put in the dorm
• literally: place at/in the dorm

After verbs like 放, 在 + place often tells where something is put:

• 放在桌子上 = put on the table
• 放在包里 = put in the bag
• 放在宿舍 = put in the dorm

So 在宿舍 tells us the final location of 资料.

资料 usually means materials, data, documents, or reference material, depending on context.

In this sentence, it most naturally means something like:

• class materials
• study materials
• documents
• handouts
• reference materials

It is a fairly broad word. It does not necessarily mean only digital data. In everyday student life, 资料 often refers to paper or study materials you need for class.

下午上课的时候 means when having class this afternoon or during class this afternoon.

Breakdown:

• 下午 = afternoon
• 上课 = attend class / have class
• 的时候 = when / at the time when

So the whole phrase is a time expression telling us when the speaker will need the materials.

A natural English translation is:

• I’ll need them when I have class this afternoon.
• I’ll need them during class this afternoon.

的 connects the action 上课 with the noun 时候.

• 时候 means time or moment
• 上课的时候 literally means the time of attending class

This is a very common pattern:

• 吃饭的时候 = when eating
• 下雨的时候 = when it rains / when it is raining
• 老师说话的时候 = when the teacher is speaking

So 的 helps turn the verb phrase into something that can modify 时候.

上课 usually means have class, be in class, or attend class, depending on context.

In this sentence, 下午上课的时候要用 most naturally means:

• I’ll need them when I have class this afternoon
• I’ll need them in class this afternoon

It does not strongly focus on the exact moment class begins. It refers more generally to the class period.

Compare:

• 去上课 = go to class
• 上课 = have class / attend class / be in class

Here 要 means will need to or am going to, not really want to.

• 要用 = will need to use / am going to use

Because the context is about class materials, the meaning is clearly:

• I’ll need to use them this afternoon in class.

要 can mean different things in different contexts:

• 我要咖啡 = I want coffee
• 我要去学校 = I’m going to school
• 这个下午要用 = this will be needed this afternoon

So in this sentence, 要 expresses future necessity or expectation.

The object is omitted because it is already clear from context: 资料.

So:

• 下午上课的时候要用

really means:

• (我) 下午上课的时候要用(资料)

Chinese often leaves out words that are understood already. Since 资料 was just mentioned, there is no need to repeat it.

This is very natural in Mandarin.

Yes, but the meaning and style may shift a little.

You could say:

• 我的资料放在宿舍了，下午上课的时候要用。
• 我把资料放在宿舍了，下午上课的时候要用。

The version with 把 emphasizes what happened to the materials: you put/left them in the dorm.

The version without 把 may sound more like stating where the materials are.

So both can work, but 把 is especially natural when the speaker is talking about handling an object and its resulting location.

No, that is not the normal word order.

With this kind of sentence, the location phrase stays closely connected to the verb:

• 放在宿舍

And 了 normally comes after the whole verb phrase, or at the end of the clause:

• 我把资料放在宿舍了。

Not:

• 我把资料放了在宿舍。

So the correct order here is:

• 把 + object + verb + location + 了

Usually 宿舍 means a dormitory or living quarters provided by a school or workplace.

Most commonly, learners first see it meaning:

• student dorm
• school dormitory

So in this sentence, 宿舍 probably means the speaker’s dorm room or dorm building.

Depending on context, it can also refer to staff housing or company dorms, but student dorm is the most likely meaning here.