Abbottonandosi il cappotto, Sara mi dice che fuori tira vento.

It is a gerund phrase. The core form is abbottonandosi, from abbottonarsi.

• abbottonare = to button
• abbottonarsi = to button up, to button something on oneself
• abbottonandosi = buttoning up, while buttoning up

So Abbottonandosi il cappotto means something like:

• Buttoning up her coat
• While she buttons up her coat
• As she buttons up her coat

In Italian, this kind of phrase often gives the background action that happens at the same time as the main verb.

Because with the gerund, pronouns are often attached to the end of the verb.

So:

• si abbottona il cappotto = she buttons up her coat
• abbottonandosi il cappotto = buttoning up her coat

This is very common in Italian:

• lavandosi = washing oneself
• mettendosi = putting on
• sedendosi = sitting down

With infinitives and gerunds, Italian often attaches pronouns directly to the verb rather than placing them before it.

Because si here does not replace il cappotto. It shows that the action is done to herself / on herself.

Compare:

• abbottona il cappotto = he/she buttons the coat
• si abbottona il cappotto = he/she buttons up their coat

In the second version, il cappotto is still the thing being buttoned, but si shows whose body the coat is on. This is very natural Italian.

English often just says button up her coat, but Italian frequently uses this reflexive-style structure.

In sentences like this, the subject of the gerund phrase is normally understood to be the same as the subject of the main clause.

So in:

• Abbottonandosi il cappotto, Sara mi dice...

the natural reading is:

• While buttoning up her coat, Sara tells me...

That means Sara is doing both actions:

1. buttoning up her coat
2. telling me that it is windy outside

This is the standard interpretation unless the context clearly suggests otherwise.

It is the gerundio presente of abbottonarsi.

How it is built:

• infinitive: abbottonarsi
• base verb: abbottonare
• gerund: abbottonando
• add pronoun: abbottonandosi

The gerund in Italian is often used to express:

• simultaneous action: while doing
• manner: by doing
• sometimes cause or circumstance, depending on context

Here it mainly expresses simultaneous action: Sara is speaking while buttoning up her coat.

The comma separates the introductory gerund phrase from the main clause.

So the structure is:

• Abbottonandosi il cappotto, = introductory action/circumstance
• Sara mi dice che... = main statement

This is similar to English:

• Buttoning up her coat, Sara tells me...

The comma helps show that the first part sets the scene for the main action.

Mi means to me, and dice means says/tells.

So:

• Sara mi dice = Sara tells me / Sara says to me

Italian often uses an indirect object pronoun where English might choose either tells me or says to me.

A few comparisons:

• mi dice qualcosa = she tells me something
• mi dice che... = she tells me that...

Che introduces the content of what Sara says. Here it means that.

So:

• Sara mi dice che fuori tira vento

= Sara tells me that it’s windy outside

In English, that is often optional:

• She tells me that it’s windy outside
• She tells me it’s windy outside

In Italian, che is normally required in this structure.

Yes, tirare vento is an idiomatic expression meaning:

• it’s windy
• the wind is blowing

So:

• fuori = outside
• tira vento = it’s windy / the wind is blowing

Together:

• fuori tira vento = it’s windy outside

This expression may sound unusual to an English speaker because tirare often means to pull, but in weather expressions it can mean to blow.

You may also hear:

• tira un vento forte = a strong wind is blowing
• tira aria di tempesta = there’s a feeling/sign of a storm coming

It could. Both are possible, but they are slightly different in feel.

• c’è vento = there is wind / it’s windy
• tira vento = the wind is blowing / it’s windy

Tira vento can feel a bit more vivid or expressive, as if you can actually feel the wind blowing.

So:

• Fuori c’è vento = Outside it’s windy
• Fuori tira vento = Outside the wind is blowing / It’s windy outside

Both are natural; the sentence you were given simply uses the more idiomatic tirare vento expression.

Because the sentence is being presented in the present:

• Sara mi dice = Sara tells me / is telling me

Italian often uses the present tense in narration or when describing what is happening in the moment.

Depending on context, English might translate it in different ways:

• Sara tells me that it’s windy outside
• Sara says it’s windy outside

If the whole passage were in the past, you might instead see:

• Sara mi ha detto che... = Sara told me that...
• Sara mi diceva che... = Sara was telling me that...

Yes. A few natural alternatives are:

• Mentre si abbottona il cappotto, Sara mi dice che fuori tira vento.
• Sara, abbottonandosi il cappotto, mi dice che fuori tira vento.
• Sara si abbottona il cappotto e mi dice che fuori tira vento.

These are similar, but not identical in style.

• Abbottonandosi il cappotto... is compact and elegant.
• Mentre si abbottona il cappotto... is more explicit: while she buttons up her coat...
• ...e mi dice... is simpler and more direct.

The original version is very natural and uses a common Italian structure.

Here it is most naturally while buttoning.

The gerund often indicates an action happening at the same time as the main verb:

• Abbottonandosi il cappotto, Sara mi dice...
• While buttoning up her coat, Sara tells me...

It does not usually mean after buttoning up her coat in this kind of sentence.

If Italian wanted to stress after, it would more likely use something like:

• Dopo essersi abbottonata il cappotto... = After buttoning up her coat...

So the original sentence suggests simultaneity, not sequence.

Because Italian often avoids possessives when ownership is obvious, especially with clothing, body parts, and personal items.

So Italian prefers:

• si abbottona il cappotto

rather than:

• si abbottona il suo cappotto

In English, her coat sounds natural and often necessary. In Italian, the reflexive structure already makes it clear that it is her own coat, so suo is usually unnecessary unless you want extra emphasis or contrast.

For example:

• Si lava le mani = He/She washes his/her hands
• Si mette la giacca = He/She puts on his/her jacket

This is a very common pattern in Italian.