nokorimono ga aru node, suupaa ni ikanakute mo daizyoubu desu.

残り物（のこりもの） means leftovers or things left over.

In this sentence, it most naturally means leftover food. So 残り物がある means there are leftovers.

• 残る = to remain, be left over
• 物 = thing

So the word is literally something like leftover thing(s), but in everyday use it often refers to food left from an earlier meal.

In 残り物がある, the particle が marks the thing that exists.

With ある and いる, Japanese often uses this pattern:

• Noun が ある = there is/are a noun
• Noun が いる = there is/are a living thing

So:

• 残り物がある = there are leftovers

If you used は instead, it would sound more like you are making 残り物 the topic, possibly with some contrast:

• 残り物はある = as for leftovers, there are some

That can work in the right context, but がある is the basic, natural existence pattern.

Because 残り物 is not a living thing.

Japanese usually distinguishes existence like this:

• ある for inanimate things
• いる for people and animals

So:

• 本がある = there is a book
• 犬がいる = there is a dog

Since leftovers are objects, ある is the correct verb.

ので means because or since.

In this sentence:

• 残り物があるので = because there are leftovers / since we have leftovers

A common learner question is how ので differs from から.

Very roughly:

• ので sounds a bit softer, more explanatory, and sometimes more formal
• から can sound more direct

So both of these are possible:

• 残り物があるので、スーパーに行かなくても大丈夫です。
• 残り物があるから、スーパーに行かなくても大丈夫です。

Both mean basically the same thing, but ので has a slightly gentler, more explanatory feel.

The sentence has two main parts:

1. 残り物があるので

   • because there are leftovers

2. スーパーに行かなくても大丈夫です

   • it is okay even if we do not go to the supermarket

So the full structure is:

• Reason + result

More literally:

• Because there are leftovers, it is okay even if we do not go to the supermarket.

This is why the natural English meaning becomes something like:

• We don’t need to go to the supermarket because there are leftovers.

With the verb 行く, に often marks the destination.

So:

• スーパーに行く = go to the supermarket

You can also often use へ with 行く:

• スーパーへ行く

Both mean go to the supermarket.

Very generally:

• に is the most common, straightforward destination marker
• へ can feel a little more directional, like toward

In this sentence, スーパーに is perfectly natural.

It comes from the verb 行く:

1. 行く = go
2. 行かない = do not go
3. 行かなくて = not going / without going
4. 行かなくても = even if not going / even if one does not go

So the pattern is:

• negative form + ても

For 行く, that becomes:

• 行かない → 行かなくて → 行かなくても

This is a very useful pattern to learn.

Examples:

• 食べなくてもいい = you do not have to eat / it’s okay not to eat
• 行かなくてもわかる = I can understand without going

Not exactly.

By itself, 行かなくても literally means something closer to:

• even if (someone) does not go
• without going

The meaning don’t have to go comes from the full phrase:

• 行かなくても大丈夫です
• literally: It is okay even if (you/I/we) do not go

That is why it sounds natural in English as:

• You/I/we don’t need to go
• It’s okay not to go

So the idea of no necessity comes from 行かなくても + 大丈夫です, not from 行かなくても alone.

Here, も gives the sense of even in the pattern ～ても / ～でも.

So:

• 行っても = even if (someone) goes
• 行かなくても = even if (someone) does not go

This is why the phrase can feel like:

• even if we don’t go, it’s fine

That even if feeling is an important part of the grammar.

Here, 大丈夫です means:

• it’s okay
• it’s fine
• there’s no problem

So:

• スーパーに行かなくても大丈夫です = it’s okay if we don’t go to the supermarket

A lot of learners first meet 大丈夫 as something like all right, okay, or safe, but in everyday Japanese it is used very broadly.

In this sentence, it does not mean physical safety. It means more like:

• we’ll be fine
• it won’t be a problem

It is omitted.

Japanese very often leaves out subjects when they are clear from context. So this sentence does not explicitly say:

• I
• we
• you

The listener figures it out from the situation.

Depending on context, this could mean:

• I don’t need to go to the supermarket
• We don’t need to go to the supermarket
• You don’t need to go to the supermarket

In many everyday situations, we or I would be the most natural understanding here.

Yes.

A casual version could be:

• 残り物があるから、スーパーに行かなくても大丈夫。

Changes:

• ので → から = a bit more casual/direct
• です is dropped for casual speech

Another common way to express the idea is:

• スーパーに行かなくてもいいです。
  • It’s okay not to go to the supermarket.

Or more directly:

• スーパーに行く必要はありません。
  • There is no need to go to the supermarket.

Your original sentence sounds natural and polite, with a soft explanatory tone.

Because Japanese and English package this idea differently.

The Japanese says, more literally:

• Because there are leftovers, it is okay even if we do not go to the supermarket.

But natural English usually prefers:

• We don’t need to go to the supermarket because there are leftovers.

So the translation changes the structure to sound natural in English, even though the Japanese grammar is built around:

• reason
• then it’s okay even if not do X

This is very common when translating Japanese into smooth English.