Pendant que nous étions en train de ranger les outils, Paul a demandé si nous avions encore besoin de la pelle et du râteau.

Pendant que means while and must be followed by a clause with a verb: pendant que nous étions...

By contrast, pendant by itself is usually followed by a noun:

• pendant la réunion = during the meeting
• pendant deux heures = for two hours

So here, because the next part contains a full action with a verb, pendant que is the correct choice.

Both are possible, but être en train de + infinitive strongly emphasizes that an action was in progress.

So:

• nous rangions les outils = we were putting away the tools
• nous étions en train de ranger les outils = we were in the middle of putting away the tools

The version with en train de is a little more explicit and vivid. It highlights the ongoing nature of the action.

The imperfect is commonly used for:

• ongoing actions in the past
• background description
• actions happening at the same time as another past event

Here, nous étions en train de ranger les outils sets the background scene: the action was already underway when something else happened.

That is exactly the kind of situation where French normally uses the imperfect.

Because a demandé refers to a completed event: Paul asked the question at a particular moment.

This creates a very common contrast in French:

• imperfect for the ongoing background action
• passé composé for the event that happened during that background action

So the structure is:

• Pendant que nous étions en train de ranger les outils = ongoing background
• Paul a demandé... = single completed action

This is similar to English We were putting away the tools when Paul asked...

Here si means whether / if in an indirect yes-no question.

The direct question would be:

• Avez-vous encore besoin de la pelle et du râteau ?

When that is reported indirectly after a demandé, French uses si:

• Paul a demandé si nous avions encore besoin...

So this si does not mean the conditional if of if it rains. It introduces an indirect question.

Because the main verb is in the past: Paul a demandé.

French usually shifts the dependent clause back into a past tense when reporting a question or statement from the past. Since having need is a state that was true at that moment, the imperfect is natural:

• direct: Avez-vous encore besoin... ?
• reported: Il a demandé si nous avions encore besoin...

So avions matches the past reporting context.

Avoir besoin de is the standard French expression for to need.

Literally, it is closer to to have need of.

Examples:

• J’ai besoin d’aide. = I need help.
• Nous avons besoin de temps. = We need time.

So in the sentence:

• nous avions encore besoin de... = we still needed / still had need of...

It is a fixed expression, so learners should remember it as a whole: avoir besoin de quelque chose.

That is because avoir besoin de is followed by de, and then the article depends on the gender of the noun:

• la pelle is feminine singular, so it stays de la pelle
• le râteau is masculine singular, so de + le contracts to du râteau

So:

• besoin de la pelle
• besoin du râteau

This is the same pattern you see in many French structures:

• de + le = du
• de + les = des

Because the sentence is referring to specific tools, not just any shovel or rake.

French often uses definite articles where English might also use the:

• la pelle = the shovel
• le râteau = the rake

If the meaning were a shovel and a rake, you would expect:

• d’une pelle et d’un râteau

So the definite articles tell us these are identifiable items in the situation, probably tools already present among the ones being put away.

Yes. That would also be correct and would sound very natural.

Compare:

• Pendant que nous rangions les outils = while we were putting away the tools
• Pendant que nous étions en train de ranger les outils = while we were in the middle of putting away the tools

The second version is more explicit and slightly more emphatic about the action being in progress. The first is shorter and often more natural in everyday French.

French usually requires an article before a noun in cases where English may use no article.

So French says:

• ranger les outils not normally
• ranger outils

Here les outils means the tools. It refers to a known set of tools in the context.

Here encore means still.

So:

• nous avions encore besoin de... = we still needed...

This is a very common use of encore. It can also mean again in other contexts, but here the meaning is clearly still, because Paul is asking whether the tools are still needed at that moment.

Because est-ce que is used to form a direct question, not usually an indirect one.

Direct question:

• Est-ce que vous avez encore besoin de la pelle et du râteau ?

Indirect reported version:

• Paul a demandé si nous avions encore besoin de la pelle et du râteau.

Once the question is embedded after a demandé, French normally uses si, not est-ce que.