syokuryou ga sukunai toki ha, kandume ga aru dake de kanari tasukarimasu.

• 食料 = しょくりょう
• 少ない = すくない
• とき / 時 = とき
• 缶詰 = かんづめ
• かなり = かなり
• 助かります = たすかります

So the full sentence is read:

しょくりょう が すくない とき は、かんづめ が ある だけ で かなり たすかります。

It breaks into two main parts:

1. 食料が少ないときは
   = when food is scarce / when there isn’t much food

2. 缶詰があるだけでかなり助かります
   = just having canned food helps a lot

A very literal structure is:

• [food is scarce] time,
• [just canned food existing] is quite helpful

Japanese often builds sentences this way: a time/condition phrase first, then the main statement.

Because 食料 is the subject of 少ない inside the phrase 食料が少ない.

So this part means:

• 食料が少ない = food is scarce

In subordinate clauses like this, が is very common and natural for the subject.

If you said 食料は少ない, that would sound more like a separate topic statement, such as as for food, it’s scarce, which has a slightly different feel. In this sentence, が is the normal choice.

Yes. 少ないとき is part of a relative-clause-style structure.

Japanese often puts a clause directly before a noun:

• 食料が少ない = food is scarce
• とき = time

So:

• 食料が少ないとき = the time when food is scarce
• more naturally, when food is scarce

There is no separate word like English when here. Japanese just uses [clause] + とき.

In 食料が少ないときは, the whole phrase 食料が少ないとき is being marked as the topic or setting.

So it has a nuance like:

• as for when food is scarce...
• when food is scarce, ...

The は helps frame the situation the speaker is talking about. It can also add a mild contrastive feeling, as in in times like that.

Without は, the sentence would still be understandable, but ときは sounds very natural when setting up the context.

食料 means food supplies, provisions, or available food stock.

That fits this sentence well because the idea is not just food in a general sense, but the amount of food available.

By contrast:

• 食べ物 = food / things to eat
• 食料 = food supply / provisions

So in a situation involving shortage, 食料 sounds more appropriate.

This is a very important pattern.

• 缶詰がある = there is canned food / we have canned food
• だけ = only / just
• で here means something like with, by, or just from that alone

So:

• 缶詰があるだけで = just by having canned food
• or the mere fact that there is canned food is enough to help

The feeling is that even that one thing alone makes a big difference.

Yes. A sentence can have more than one が if they belong to different parts of the sentence.

Here:

• 食料が少ない → 食料 is the subject of 少ない
• 缶詰がある → 缶詰 is the subject of ある

So the two が are doing different jobs in different chunks.

This is completely normal in Japanese.

だけで often means:

• just by ...
• with only ...
• merely ... is enough to ...

Examples:

• 見るだけで分かる = I can tell just by looking
• 水だけで生きるのは無理です = It’s impossible to live on only water
• 缶詰があるだけで助かる = Just having canned food helps

So in your sentence, だけで expresses that one fact alone is enough to produce the helpful result.

助かります comes from 助かる, which literally means things like:

• to be saved
• to be helped
• to be relieved

In everyday Japanese, it often means:

• That helps a lot
• That’s a big help
• What a relief

So here, かなり助かります does not sound dramatic like my life is saved. It sounds natural and practical: that would really help.

This is one of those very common Japanese expressions that often sounds more natural than translating with a direct English verb like help.

Because 缶詰 is an inanimate thing.

Japanese uses:

• ある for inanimate things
• いる for animate beings like people and animals

So:

• 缶詰がある = there is canned food
• not 缶詰がいる

かなり means:

• quite
• considerably
• pretty
• a lot

So:

• かなり助かります = it helps quite a lot
• it’s a big help
• it would be pretty helpful

It strengthens the statement without sounding extreme.

Japanese nouns usually do not show singular vs. plural clearly unless the context makes it clear.

So 缶詰 here could mean:

• a can of food
• some canned food
• canned goods

The sentence is really about the existence of canned food as a resource, not the exact number.

So the most natural English rendering is often just canned food.

Yes. だけでも is very natural too:

• 缶詰があるだけでもかなり助かります

This adds the nuance of:

• even just having canned food helps a lot

Compared with だけで, だけでも sounds a little more emphatic about how even that minimal amount is valuable.

Both are natural, but:

• だけで = just that alone is enough
• だけでも = even just that much is already helpful

Yes. It can be written as 時:

• 食料が少ない時は、缶詰があるだけでかなり助かります。

In many learning materials, とき is written in hiragana because it is easy to read and very common. Both are fine.