zhìyuànzhě zhèngzài fāfàng shēnghuóyòngpǐn.

正在 marks an action as in progress right now. It is similar to is/are ...-ing in English.

So 志愿者正在发放生活用品 means the distributing is happening at this moment or during the current scene.

A very common pattern is:

Subject + 正在 + Verb + Object

Here:

• 志愿者 = subject
• 正在 = progressive marker
• 发放 = verb
• 生活用品 = object

Yes. 在发放 is also natural.

The difference is mainly one of emphasis:

• 在发放 = the action is ongoing
• 正在发放 = also ongoing, but often feels a bit more explicit or slightly more formal/emphatic

So these are both fine:

• 志愿者在发放生活用品。
• 志愿者正在发放生活用品。

In news reports or captions, 正在 is especially common.

It can mean one volunteer or volunteers. Chinese nouns often do not change form for singular vs. plural.

You figure it out from context.

So 志愿者正在发放生活用品 could mean:

• A volunteer is distributing supplies
• Volunteers are distributing supplies

If you really want to stress plural, you can say 志愿者们, but that is often unnecessary.

Because 们 is optional in many cases, and Chinese often leaves plural unmarked when the meaning is already clear.

Using 志愿者们 can sound more specific or more like the volunteers as a known group. Without 们, the sentence sounds more neutral and natural in many contexts, especially captions, news writing, or general descriptions.

So:

• 志愿者正在发放生活用品。 = neutral, very natural
• 志愿者们正在发放生活用品。 = also correct, with a bit more group emphasis

Because this is an action sentence, not an A is B sentence.

是 is used when you identify or equate things:

• 他是志愿者。 = He is a volunteer.

But when the subject is doing something, Chinese usually just uses the verb directly:

• 志愿者正在发放生活用品。

So English often needs is/are, but Chinese does not put 是 before a normal action verb.

发放 means to distribute, to hand out, or to issue something, usually in an organized way.

It is more formal and specific than just 发, which can simply mean to send out, to hand out, or to give out.

发放 is often used for things like:

• relief supplies
• benefits
• leaflets
• coupons
• materials
• aid

So in this sentence, 发放 fits well because volunteers are distributing items systematically, not just casually handing over one thing.

生活用品 means daily necessities, everyday supplies, or items for daily life.

It is made up of:

• 生活 = life / daily living
• 用品 = articles for use / supplies / goods for use

Depending on context, it can include things like:

• soap
• toothpaste
• towels
• clothing
• blankets
• basic household items

In disaster relief or charity contexts, it often means basic living supplies.

A related word is 日用品, which also means daily-use items. The two can overlap a lot.

Because Chinese usually follows this basic order:

Subject + adverb/aspect marker + verb + object

So here:

• 志愿者 = who is doing the action
• 正在 = marks the action as ongoing
• 发放 = the action
• 生活用品 = what is being distributed

This is very normal Chinese word order.

English says:

• The volunteers are distributing supplies

Chinese says, more literally:

• Volunteers currently distributing daily supplies

The grammar works differently, but the order is standard.

Because Chinese does not have articles like English.

So Chinese usually does not directly mark:

• a
• an
• the

Whether something is definite or indefinite usually comes from context.

That is why:

• 志愿者 can mean a volunteer, the volunteer, or volunteers
• 生活用品 can mean supplies, the supplies, or some daily necessities

If Chinese wants to be more specific, it uses other tools, such as:

• context
• demonstratives like 这些 or 那些
• numbers and classifiers

For example:

• 这些生活用品 = these supplies
• 一些生活用品 = some supplies

Because classifiers are usually needed when there is a number or a demonstrative.

For example:

• 一些生活用品 = some daily necessities
• 这批生活用品 = this batch of supplies
• 三箱生活用品 = three boxes of supplies

But in the original sentence, 生活用品 is just a general object, so no classifier is required.

That is very normal.

Usually, not in the same way.

正在 shows an action is ongoing, while 了 often marks completion or a new situation. Because of that, beginners should normally keep them separate here:

• 志愿者正在发放生活用品。 = The volunteers are distributing supplies.
• 志愿者发放了生活用品。 = The volunteers distributed the supplies / have distributed supplies.

If you want to sound more natural while emphasizing that the action is happening right now, 呢 is often possible:

• 志愿者正在发放生活用品呢。

So as a beginner, it is safest to think:

• 正在 = in progress
• 了 = completed / changed situation

It is natural, but it has a slightly formal / report-like tone.

That comes mainly from:

• 正在
• 发放
• 生活用品

This kind of wording is very common in:

• news reports
• public announcements
• captions
• charity or disaster-relief descriptions

In everyday conversation, people might say something a bit simpler, such as:

• 志愿者在发生活用品。
• 志愿者在给大家发东西。

So the original sentence is correct and natural, but it sounds a little more official or written.

者 is a suffix meaning person, especially a person connected with an action, role, or identity.

So:

• 志愿 relates to volunteering / willingness
• 志愿者 = volunteer = a person who volunteers

You can see the same 者 in other words:

• 记者 = reporter
• 读者 = reader
• 作者 = author
• 患者 = patient

It is a very useful suffix to recognize because it often tells you that the whole word refers to a person.