atarasii suponzi no hou ga huruino yori tukaiyasui.

In this sentence, A のほうが B より ... is a very common comparison pattern:

• A のほうが = A is the one that is more...
• B より = than B

So:

• 新しいスポンジのほうが = the new sponge is the one that...
• 古いのより = than the old one

A very natural whole pattern is:

• A のほうが B より adjective
• A is more adjective than B

Here, the adjective is 使いやすい = easy to use.

That の connects スポンジ to ほう.

Literally, ほう means something like side, direction, or one of the two. In comparisons, A のほう means the A side or more naturally the A one.

So:

• 新しいスポンジのほう = the new-sponge side / the new one
• 古いのより = than the old one

This is just how the comparison expression is built in Japanese. You normally say:

• A のほうが B より ...

not:

• A ほうが B より ...

ほう does not mean side in a literal physical sense here. In comparisons, it means something like:

• the one
• the side
• the option

So 新しいスポンジのほうが means:

• the new sponge, rather than the old one
• the new one is the one that...

This structure is especially common when comparing two things.

Because の can stand in for a noun that is understood from context.

So:

• 古いスポンジ = the old sponge
• 古いの = the old one

This is very common in Japanese. It avoids repeating the noun when it is already obvious.

Other examples:

• 赤いの = the red one
• 大きいの = the big one
• 便利なの = the convenient one

In your sentence, 古いの clearly means the old sponge or the old one.

Yes, in this sentence より means than in a comparison.

So:

• 古いのより = than the old one

A basic pattern is:

• A は B より adjective = A is more adjective than B

and also:

• A のほうが B より adjective = A is more adjective than B

The second version often sounds more explicit or more like you are choosing between two things.

In standard comparison sentences, が is very common after ほう.

So:

• 新しいスポンジのほうが古いのより使いやすい = The new sponge is easier to use than the old one

Here, が marks the thing being identified as having the stronger quality.

You may also see は in some contexts, but A のほうが B より... is the very standard comparison pattern learners should remember.

So the safest takeaway is:

• のほうが is a set pattern in comparisons

使いやすい means easy to use.

It is made from:

• 使う = to use
• やすい = easy to do

When attached to the verb stem, やすい creates an adjective meaning easy to ...

So:

• 使う → verb stem 使い
• 使い + やすい = 使いやすい
• easy to use

This pattern is very useful:

• 読みやすい = easy to read
• 書きやすい = easy to write
• 分かりやすい = easy to understand

Because this sentence is in plain style.

• 使いやすい ends the sentence in casual/plain form.
• A polite version would be:
  • 新しいスポンジのほうが古いのより使いやすいです。

Both are grammatically fine. The version without です is just less polite and more neutral/casual.

Yes, 古いのより is natural.

Since スポンジ was already mentioned, Japanese often avoids repeating it. So:

• 古いスポンジより = than the old sponge
• 古いのより = than the old one

Both work, but 古いのより sounds more concise and natural when the noun is already clear.

Yes. Japanese word order is flexible as long as the particles stay correct.

For example, these mean basically the same thing:

• 新しいスポンジのほうが古いのより使いやすい。
• 古いのより、新しいスポンジのほうが使いやすい。

The second version puts the than... part earlier for emphasis or flow.

The core grammar is still:

• A のほうが B より adjective

Japanese nouns usually do not mark singular vs. plural the way English does.

So スポンジ can mean:

• a sponge
• sponges
• the sponge
• sponge(s) as a general item

In this sentence, context strongly suggests a single sponge being compared with another single sponge, so the natural English meaning is the new sponge and the old one.

Yes, that is grammatically possible, but it is a slightly different structure.

• 新しいスポンジは古いのより使いやすい = As for the new sponge, it is easier to use than the old one

• 新しいスポンジのほうが古いのより使いやすい = The new sponge is easier to use than the old one

The のほうが version sounds more directly comparative, especially when choosing between two items. That is why it is very common here.

It can do either, depending on context.

It could mean:

• two actual sponges in front of you:
  • The new sponge is easier to use than the old one.
• or a more general statement:
  • New sponges are easier to use than old ones.

Japanese often leaves that kind of detail to context. The grammar itself does not force only one interpretation.

The main pattern is:

• A のほうが B より adjective

Meaning:

• A is more adjective than B

In your sentence:

• A = 新しいスポンジ
• B = 古いの
• adjective = 使いやすい

So the full structure is:

• 新しいスポンジのほうが古いのより使いやすい。
• The new sponge is easier to use than the old one.

This is a very useful comparison pattern and worth memorizing.