Il cavalletto resta fermo anche quando il vento soffia forte.

Italian uses articles more often than English does. Here, il cavalletto means the tripod/easel and refers to a specific item, or one that is already understood from context.

In English, we sometimes drop the article in short descriptions, but in a full Italian sentence, the article is usually needed.

Resta is the third-person singular present of restare.

Here, resta fermo means stays still or remains still.

So the idea is not just that the object is still, but that it continues to be still, even under difficult conditions.

Both are possible, but they are not exactly the same.

• è fermo = it is still
• resta fermo = it stays/remains still

Resta adds the idea of continuing in that state. In this sentence, that matters, because the wind could make it move, but it still remains steady.

Fermo is an adjective describing il cavalletto, so it has to agree with that noun.

Since cavalletto is:

• masculine
• singular

the adjective must also be masculine singular: fermo.

Examples:

• il cavalletto resta fermo
• la sedia resta ferma
• i cavalletti restano fermi

Yes. Restare and rimanere are very close in meaning here.

• Il cavalletto resta fermo
• Il cavalletto rimane fermo

Both are natural and correct. In many contexts, the difference is very small. A learner can usually treat them as near-synonyms in this kind of sentence.

Here, anche quando means even when.

Literally:

• quando = when
• anche = also / even

In this sentence, anche gives a concessive idea: even under that condition.

So:

• anche quando il vento soffia forte = even when the wind blows hard

Because forte is very commonly used in Italian in an adverb-like way after certain verbs.

So although forte is normally an adjective, in sentences like this it works naturally as hard / strongly.

Examples:

• parlare forte = to speak loudly
• piovere forte = to rain hard
• soffiare forte = to blow hard

Fortemente exists, but here it sounds much less natural and more formal or abstract.

Italian often uses the present tense for:

• general truths
• habitual situations
• descriptions of how something behaves

So this sentence can mean something like:

The tripod stays still even when the wind blows hard.

It describes a general characteristic, not necessarily one single event happening right now.

Yes. Soffia is the present indicative.

After quando meaning when, Italian normally uses the indicative when talking about a real or habitual situation:

• quando piove
• quando arriva
• quando il vento soffia forte

So there is nothing unusual here.

Yes, that is possible, but it is less neutral.

The standard, most straightforward order is:

quando il vento soffia forte

If you say:

quando soffia forte il vento

it can sound more literary, more emphatic, or more stylistically marked. A learner should usually stick with the more basic order first.

Because the subordinate clause is closely connected to the main clause:

Il cavalletto resta fermo anche quando il vento soffia forte.

In Italian, a comma is often not used before a clause like this when it directly completes the meaning of the sentence.

A comma could appear for special emphasis or rhythm, but without one, this is completely normal and standard.