chǔwùguì zài línyùshì pángbiān.

Chinese often states location with this pattern:

thing + 在 + place

So here:

• 储物柜 = the locker / lockers
• 在 = is/are located at
• 淋浴室旁边 = beside the shower room

That makes 储物柜 在 淋浴室 旁边 a very standard sentence pattern for saying where something is.

A useful formula is:

A 在 B 附近 / 旁边 / 里面 / 外面
= A is near / next to / inside / outside B

In Chinese, when you say where something is located, 在 often does the job that English is/are would do in a sentence like this.

So:

• 储物柜在淋浴室旁边。 = The locker(s) are beside the shower room.

You would not usually say 储物柜是...旁边 here.
Using 是 for physical location is generally incorrect.

Compare:

• 他是老师。 = He is a teacher.
  
  • 是 links two nouns.
• 他在教室。 = He is in the classroom.
  
  • 在 shows location.

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

It is a very common location word in Chinese. It usually comes after a place noun:

• 学校旁边 = beside the school
• 桌子旁边 = beside the table
• 淋浴室旁边 = beside the shower room

So in your sentence, 淋浴室旁边 is one chunk meaning beside the shower room.

Because 旁边 is acting as a localizer or location word, and in Chinese these often attach directly to the noun before them.

So these are natural:

• 桌子上面 = on the table
• 房子后面 = behind the house
• 淋浴室旁边 = beside the shower room

Adding 的 here would usually sound unnatural in a basic location sentence.

Think of it as:

noun + location word

rather than

noun + 的 + location word

It can be either singular or plural, depending on context.

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

So 储物柜 can mean:

• the locker
• the lockers
• a locker
• lockers

Context tells you which one is meant.

If you want to be more specific, you can add a number and measure word:

• 一个储物柜 = one locker
• 两个储物柜 = two lockers

储物柜 literally means something like storage cabinet/locker, and it is a good word for a locker in places like gyms, pools, or public facilities.

You may also hear:

• 柜子 = cabinet / cupboard / locker-like unit
  
  • more general
• 寄存柜 = storage locker / deposit locker
  
  • often for temporary public use
• 更衣柜 = changing-room locker
  
  • specifically in changing areas

So 储物柜 is correct, but the most natural choice can depend on the setting.

在 is a broad location word. Depending on context, it can correspond to English in, at, on, or just be located at.

Examples:

• 我在家。 = I’m at home.
• 书在桌子上。 = The book is on the table.
• 他在房间里。 = He is in the room.

In your sentence, 在 simply marks the location relationship:

• 储物柜在淋浴室旁边。 = The locker(s) are next to the shower room.

The more precise spatial meaning comes from 旁边, not from 在 alone.

Usually, 旁边 is the safer and more natural choice for learners.

• 旁边 = beside / next to
• 旁 by itself can appear in certain expressions, but it is less commonly used alone in everyday beginner-style location sentences.

So:

• 淋浴室旁边 = natural
• 淋浴室旁 = possible in some contexts or styles, but less standard for beginners

If you want to sound natural, use 旁边.

It is pronounced:

chǔwùguì zài línyùshì pángbiān

Tone by tone:

• 储 chǔ — 3rd tone
• 物 wù — 4th tone
• 柜 guì — 4th tone
• 在 zài — 4th tone
• 淋 lín — 2nd tone
• 浴 yù — 4th tone
• 室 shì — 4th tone
• 旁 páng — 2nd tone
• 边 biān — 1st tone

A natural rhythm is:

储物柜 / 在 / 淋浴室旁边。

Yes, but it is usually a little less direct and often less natural than 淋浴室旁边 in a simple sentence like this.

Compare:

• 储物柜在淋浴室旁边。 = very natural
• 储物柜在淋浴室的旁边。 = understandable, sometimes acceptable, but often unnecessary

In basic location expressions, Chinese commonly prefers:

place + localizer

So 淋浴室旁边 is the form you should learn first.

A natural question is:

储物柜在哪儿？
or
储物柜在哪里？

Both mean Where are the lockers?

Then the answer can be:

储物柜在淋浴室旁边。

This is a very useful question-and-answer pattern:

• A 在哪儿？ = Where is/are A?
• A 在 B 旁边。 = A is beside B.

Yes. It is short, complete, and natural.

Chinese often allows very concise location sentences, especially in signs, directions, or simple descriptions.

So 储物柜在淋浴室旁边。 works well as:

• a spoken answer
• a simple description
• a directional explanation

It does not need extra words to be grammatical.