tukue wo kabegiwa ni oku to, heya wo motto hiroku tukaemasu.

壁ぎわ is read かべぎわ.

It means by the wall, along the wall, or right next to the wall.

It is often written as 壁際 in kanji, but 壁ぎわ is also very common in learner-friendly writing because 際 can be harder to read.

So in this sentence:

机を壁ぎわに置く
= put the desk by the wall

に marks the place where something is put.

With verbs of placement like 置く, に often shows the destination or location where the object ends up.

So:

• 机を壁ぎわに置く = put the desk at/by the wall
• 本を机に置く = put the book on the desk

Here:

• 机を = the desk is the thing being moved/placed
• 壁ぎわに = the place where it is placed

Because 机 is the direct object of 置く.

置く means to put or to place, so the thing being placed takes を.

• 机を置く = place the desk
• 本を置く = place a book

In this sentence:

• 机を = the desk is what you place
• 壁ぎわに = where you place it

No, this と is not the and particle.

Here, と is a conditional marker. It means something like:

• if you put...
• when you put...

So:

机を壁ぎわに置くと、部屋をもっと広く使えます。
= If/when you put the desk by the wall, you can use the room more spaciously.

This と is often used for results that are natural, regular, or expected.

It gives the feeling of:

• When X happens, Y happens
• If you do X, this is the result

All three can mean something like if you put it, but the nuance is a little different.

置くと

• often sounds like a natural or predictable result
• If you put the desk by the wall, the room becomes easier to use more spaciously

置けば

• a more straightforward conditional
• often used for advice, suggestions, or logical consequences
• If you put it by the wall, you'll be able to use the room better

置いたら

• often sounds more like after you put it or if you put it
• can be used in many everyday situations
• slightly more conversational and flexible

In this sentence, 置くと fits well because the speaker is describing a general result of furniture arrangement.

Because 部屋を使う is the normal pattern for use a room.

The verb 使う takes a direct object with を:

• 部屋を使う = use the room
• 時間を使う = use time
• お金を使う = use money

The potential form 使える means can use, and with potential verbs Japanese sometimes allows either を or が depending on the verb and expression. But 部屋を使える is very natural and common here.

So:

• 部屋をもっと広く使えます = you can use the room more spaciously / make better use of the room

Because 広く is the adverb form of 広い.

• 広い = wide, spacious
• 広く = widely, spaciously

Here, 広く modifies 使えます.

So:

• 広い部屋 = a spacious room
• 部屋を広く使う = use the room in a spacious way / make spacious use of the room

This is a very common pattern:

• 大きい → 大きく
• 早い → 早く
• 広い → 広く

もっと means more.

Here it modifies 広く, so together:

もっと広く = more spaciously / in a more spacious way

So the sentence is saying that by placing the desk by the wall, you can use the room more efficiently or more spaciously than before.

It does not mean the room literally becomes bigger. It means the layout makes it feel or function as if there is more space.

使えます is the polite potential form of 使う.

• 使う = to use
• 使える = can use
• 使えます = can use / are able to use

So:

部屋をもっと広く使えます
literally = you can use the room more spaciously

A more natural English translation might be:

• You can make better use of the room
• You can use the room more efficiently
• The room will feel more spacious

Depending on context, all of these capture the idea.

The subject is omitted, which is very normal in Japanese.

Depending on context, it could mean:

• you can use the room more spaciously
• we can use the room more spaciously
• one can use the room more spaciously

Japanese often leaves out subjects when they are understood from context.

In an advice sentence like this, English usually supplies you:

• If you put the desk by the wall, you can use the room more spaciously.

Yes, it is a very natural expression.

Japanese often uses:

• 空間を広く使う = use space widely
• 部屋を広く使う = use the room spaciously
• 机を広く使う = use the desk surface widely

This means making efficient use of space so it feels less cramped.

So 部屋をもっと広く使えます does not mean changing the physical size of the room. It means arranging things so the room can be used in a more open way.

The comma helps separate the conditional clause from the main clause:

• 机を壁ぎわに置くと、 = if you put the desk by the wall,
• 部屋をもっと広く使えます。 = you can use the room more spaciously.

Japanese commas are often used more flexibly than English commas. This one makes the sentence easier to read, but the sentence could still be understood without it.

Yes.

Even though the grammar is literally stating a result, sentences like this are often used as gentle advice or a suggestion.

So it can feel like:

• If you put the desk by the wall, you'll have more usable space
• You should put the desk by the wall; then the room will feel more spacious

Japanese often gives advice indirectly by describing the likely benefit rather than directly saying Do this.