yǎlíng zài pǎobùjī pángbiān.

The pattern is:

noun + 在 + place

So in 哑铃 在 跑步机 旁边,

• 哑铃 = the dumbbell / dumbbells
• 在 = is/are located at
• 跑步机旁边 = beside the treadmill

A natural way to think about it is:

[Thing] + [is located] + [place]

So this is a very common Chinese way to say where something is.

在 is used to show location.

In this sentence, it means something like is at / is in / is on / is beside, depending on the location phrase that follows.

Here, because the location phrase is 跑步机旁边 (beside the treadmill), the whole sentence means the dumbbell is located beside the treadmill.

So 在 is not exactly translated word-for-word every time, but it is the key marker showing location.

Because Chinese normally does not use 是 to say where something is.

In English, we say:

• The dumbbell is beside the treadmill.

So learners often want to say:

• 哑铃是跑步机旁边。 ❌

But in Chinese, location is usually expressed with 在, not 是:

• 哑铃在跑步机旁边。 ✅

A useful rule:

• 是 links one noun to another noun or identifies something
  
  • 他是老师。 = He is a teacher.
• 在 tells where something is
  
  • 他在家。 = He is at home.

旁边 means beside, next to, or at the side of.

It is a location word (sometimes called a localizer).
It tells you the position relative to something else.

So:

• 跑步机旁边 = beside the treadmill
• literally: treadmill + side

Other common location words work similarly:

• 上面 = on top of / above
• 下面 = under / below
• 里面 = inside
• 外面 = outside
• 前面 = in front
• 后面 = behind

Because 旁边 usually needs a reference point: beside what?

So:

• 跑步机旁边 = beside the treadmill
• 桌子旁边 = beside the table
• 门旁边 = beside the door

You can say just 旁边 if the reference is already obvious from context, but in a full sentence like this, Chinese usually includes the thing being referred to.

Because with noun + location word combinations, 的 is usually not needed.

So these are normal:

• 桌子上面
• 椅子下面
• 学校旁边
• 跑步机旁边

Using 的 here would usually sound unnatural or unnecessary.

A simple learner rule is:

place noun + location word
not
place noun + 的 + location word

So:

• 跑步机旁边 ✅
• 跑步机的旁边 usually not the normal choice here

It is usually treated as a location word or localizer.

It is not quite the same as an English preposition like beside.
Instead, Chinese often builds location expressions like this:

noun + localizer

For example:

• 桌子上面 = table + top side = on the table / above the table
• 椅子下面 = chair + lower side = under the chair
• 跑步机旁边 = treadmill + side = beside the treadmill

So in this sentence:

• 在 introduces the location
• 跑步机旁边 is the location phrase

Chinese and English organize location a little differently.

English:

• The dumbbell is beside the treadmill.

Chinese:

• 哑铃 在 跑步机旁边。

A useful way to view the Chinese order is:

• thing + at/in/on + place

This order is very common in Chinese:

• 书在桌子上。 = The book is on the table.
• 猫在椅子下面。 = The cat is under the chair.
• 哑铃在跑步机旁边。 = The dumbbell is beside the treadmill.

So even if the English translation uses is beside, Chinese naturally uses 在 + place.

Chinese does not have articles like a, an, and the.

So a bare noun like 哑铃 can mean:

• a dumbbell
• the dumbbell
• dumbbells

The exact meaning depends on context.

If Chinese wants to be more specific, it can add other words:

• 一个哑铃 = a dumbbell
• 那个哑铃 = that dumbbell
• 这些哑铃 = these dumbbells

But when the context already makes it clear, Chinese often just uses the noun by itself.

By itself, 哑铃 does not clearly show singular or plural.

Chinese nouns usually do not change form for plural the way English nouns do.

So depending on context, 哑铃 could mean:

• the dumbbell
• a dumbbell
• dumbbells

If you want to make it clearer, you can add a number or determiner:

• 一个哑铃 = one dumbbell
• 两个哑铃 = two dumbbells
• 这对哑铃 = this pair of dumbbells

So the sentence itself does not force singular/plural in the same way English often does.

It is understandable, but it is usually not the most natural way to say it.

The normal expression is:

• 哑铃在跑步机旁边。

In standard everyday Chinese, location expressions usually go directly like this:

• 桌子上
• 沙发后面
• 学校附近
• 跑步机旁边

So it is best to learn noun + location word as one unit.

Not in a normal complete sentence like this.

You need 在 to say where something is:

• 哑铃在跑步机旁边。 ✅

Without 在:

• 哑铃跑步机旁边。 ❌

That does not work as a complete standard sentence.

So when you are saying something is located somewhere, keep 在.

Yes. A few similar expressions are:

• 旁边
• 边上
• 旁
• sometimes 旁侧 in more formal language

For everyday speech, 旁边 is one of the safest and most common choices.

For example:

• 哑铃在跑步机边上。 This is also natural and means almost the same thing.

A couple of things learners may notice:

• 哑铃 = yǎlíng

  • 哑 is third tone
  • 铃 is second tone

• 跑步机 = pǎobùjī

  • 跑 third tone
  • 步 fourth tone
  • 机 first tone

• 旁边 = pángbiān

  • 旁 second tone
  • 边 first tone

Also, when spoken naturally, tones may sound slightly smoother or less isolated than in careful dictionary pronunciation, but the underlying tones stay the same.

It describes location, not action.

Here, 在 is not the progressive marker meaning -ing.
It is the location word meaning at / in / on.

So this sentence is not saying the dumbbell is doing anything.
It is only saying where it is.

Compare:

• 哑铃在跑步机旁边。
  = The dumbbell is beside the treadmill.

• 他在跑步。
  = He is running.

The same written word 在 can appear in different grammar patterns, so context matters. Here it is clearly the location use.