Még ha nagy is a tepsi, használjuk.

Ha means if.

Adding még makes it stronger: még ha = even if.

So this introduces a concessive idea: the thing in that clause does not stop the action in the main clause.

• ha nagy a tepsi = if the tray is big
• még ha nagy is a tepsi = even if the tray is big

No. Hungarian is is not the verb to be.

It is a particle that often means also / too, but in patterns like még ha ... is, it helps create the meaning even if.

So in this sentence, is is part of the concessive structure, not the verb.

That is a very common source of confusion for English speakers because it looks identical to English is.

In Hungarian, the present-tense verb van (to be) is usually omitted in 3rd person singular when the sentence is something like X is Y.

So:

• A tepsi nagy. = The tray is big.

There is no spoken van there.

The same thing is happening in this sentence. The copula is understood, not stated.

So nagy is a tepsi still means the tray is big, just in a special word order used in this structure.

Because Hungarian word order is flexible, and here the sentence is highlighting the idea big inside the even if clause.

The neutral statement would be:

• A tepsi nagy. = The tray is big.

But in the concessive pattern még ha ... is, Hungarian often puts the predicate first:

• Még ha nagy is a tepsi...

This makes nagy the prominent element: even if it is big.

So the word order is not random; it reflects emphasis and a common Hungarian clause pattern.

A is the definite article, meaning the.

So:

• tepsi = tray / baking tray
• a tepsi = the tray

Hungarian uses the definite article very regularly when talking about a specific, identifiable thing.

Because Hungarian verbs have two main conjugation types:

• indefinite conjugation
• definite conjugation

Használunk means we use in a general or indefinite sense.

Használjuk means we use it / we use the specific one, with a definite object.

Here, the object is understood to be a specific tray, so the definite form használjuk is used.

A useful contrast:

• Használunk egy tepsit. = We use a tray.
• Használjuk a tepsit. = We use the tray.
• Használjuk. = We use it.

Hungarian often leaves pronouns unstated when they are clear from context.

English usually needs it, but Hungarian often does not.

The ending of használjuk already tells you that the verb has a definite object, so it can be left implicit.

So:

• Használjuk. = We use it.

If you wanted to say the object explicitly for emphasis, Hungarian could do that, but it is often unnecessary.

Yes. This form can be ambiguous.

Használjuk can be:

• present indicative definite: we use it
• 1st person plural imperative/jussive definite: let’s use it

So without context, használjuk can mean either one.

Usually the surrounding context or the translation given to the learner tells you which meaning is intended.

Yes, that is also possible.

Hungarian allows some flexibility here, and both versions are understandable. The difference is mainly about emphasis and style.

• Még ha nagy is a tepsi, használjuk.
• Még ha a tepsi nagy is, használjuk.

The given version puts more focus on nagy. That is why it is a very natural choice in this kind of even if sentence.