Gardons la déclaration de sinistre au cas où l’expert la demanderait.

Gardons is the nous imperative form of garder.

That means it is not a simple statement like we keep. It is a suggestion or instruction that includes the speaker: let’s keep.

So Gardons... means Let’s keep...

In French, subject pronouns are normally omitted in the imperative.

So:

• Nous gardons = We keep / We are keeping
• Gardons = Let’s keep

That is why the sentence does not say Nous gardons. It is giving a recommendation, not stating a fact.

This is an insurance expression. It refers to a report or declaration made after damage, an accident, or some other insured loss.

A useful point for English speakers: sinistre here does not mean sinister in the English sense. In insurance French, un sinistre is a loss, claim event, or incident causing damage.

So déclaration de sinistre is best learned as a fixed phrase used in insurance contexts.

The two la forms do different jobs.

• la déclaration: here la is the definite article, meaning the
• l’expert la demanderait: here la is a direct object pronoun, meaning it

So the second la stands for la déclaration de sinistre.

Au cas où means in case.

It is best treated as a set expression.

The accent matters:

• où = where
• ou = or

In au cas où, French uses où with the grave accent. Even though English translates the whole expression as in case, the French spelling stays où.

After au cas où, standard French normally uses the conditional, especially when talking about a possible future situation.

So:

• au cas où l’expert la demanderait = in case the expert should/would ask for it

This is different from English, because English often uses a present form after in case. French does not usually do that here.

Also, this is not a subjunctive construction. Even though the event is uncertain, au cas où normally takes the conditional.

Demanderait is the present conditional, third person singular, of demander.

It corresponds to he/she would ask.

Its structure is:

• infinitive stem: demander-
• conditional ending: -ait

So:

• je demanderais
• tu demanderais
• il/elle demanderait

In French, object pronouns usually come before the conjugated verb.

So French says:

• l’expert la demanderait

Literally, that is something like:

• the expert it would ask for

But in natural English, we say:

• the expert would ask for it

This is a very common difference between French and English word order.

Because French uses elision before a vowel sound.

So:

• le expert becomes l’expert

This happens regularly with articles and other short words:

• le ami → l’ami
• je aime → j’aime

Since expert begins with a vowel sound, le must become l’.

Because French demander can take the thing requested directly.

So:

• demander quelque chose = to ask for something

That means demander la déclaration naturally means ask for the report.

If you want to say who is being asked, French uses à:

• demander la déclaration à quelqu’un = ask someone for the report

So the missing English for is normal here.

Not always. In an insurance context, l’expert often means the professional who evaluates the damage or the claim.

Depending on context, that could be translated more naturally as:

• the assessor
• the adjuster
• the claims expert

So while expert is the literal French word, the most natural English equivalent may be more specific in this kind of sentence.