Breakthrough moment—Using the correct auxilliary in Passato Prossimo

There are certain verbs that can be used with either auxilliary verb, ESSERE or AVERE, depending on if the action verb is transative or intransitive. It could be either one, so how can you tell without analyzing the sentence components and nouns? You don’t have time to do this during a conversation; it needs to be instinctual.

Take the verb POTERE, for example.
It means “to be able to”; which is commonly replaced with the single word “can”, in English.
Io posso = I am able (to); I can

I was getting very used to always using the auxilliary “avere” with “potere” when using the passato prossimo.
For example, Ho potuto (I could):

Non ho potuto nuotare. (I could not swim)
Avete potuto cantare con noi (You (all) could sing with us)

But then I came across some sentences that used “essere” as the auxilliary, which changes everything.
Now I need to match the gender and the quanity of the subjects:

Lei non è potuta venire con noi (She was not able to come with us)
Noi siamo potuti andare con loro (We could have gone with them)

What happened? I thought it was always going to be “potuto”?
The verb that follows potuto is what happened.
You cannot use the verb potere without another verb following it, unless you make the simple/ final statement: “I can”. Or “I could”.
Even then, there is a verb that is implied by those statements.
“Can you read this?” “I can.” ( this).

So then, in the case of the two sentences that use ESSERE as the auxillary, the verb following POTERE is one that you have to use ESSERE with, if used on their own; namely, VENIRE and ANDARE:

Lei è venuta alla festa (She came to the party)
Lui è venuto alla festa (He came to the party)
Sono andati a Napoli per le vacanze (They went to Naples for vacation)

In the examples that used AVERE as the auxilliary before POTERE, those being NUOTARE and CANTARE, you can see that swimming and singing are Italian verbs that would use AVERE on their own if used without POTERE:

Ho nuotato nel mare (I swam in the sea)
Abbiamo cantato le canzoni (We sang the songs)

So, to circle back:

Lei non è potuta venire con noi
This uses the auxilliary for singular (è) and “Lei” requires the feminine singular verb ending “a” (potuta), before the infinitive “venire”, which told you to use ESSERE instead of AVERE
Noi siamo potuti andare con loro
This uses the auxilliary for plural (siamo) and “Noi” requires the plural verb ending “i” (potuti), before the infinitive “andare”...

April 18, 2016


Hello Mabby,

Thank you for the post. If I understood my grammar book correctly, both options are actually possible from the language perspective:

Lei non è potuta venire con noi

Lei non ha potuto venire con noi

Is that right or not? However I understand that once we get the auxiliary verb right and automated, we will continue using the correct one also when using it together with potere...

April 19, 2016

Both are an option, I remember hearing the "non sono potuto venire" etc version every so often but during two years living in Italy, pretty much everyone said "non ho potuto venire".

A quick google led me to this article: where it is stated that both are acceptable and the "ho potuto venire" option is much more common, as I experienced.

Don't forget that the essere auxiliary can also be used with the other modal verbs dovere, volere and sapere.

The article also states that if you are emphasising the possibility (potere), obligation (dovere), desire (volere) or knowledge (sapere) more than the second verb (andare, venire etc.) then you would even more likely use the avere auxiliary.

With reflexive verbs you must use essere if the reflexive pronoun precedes the verb: "non si è potuta cambiare". However you can use avere if the reflexive pronoun goes after the verb "non ha potuto cambiarsi".

Hope this helps and thanks Mabby for another interesting article!

April 20, 2016

Thanks and congratulations on your year-long streak!

April 21, 2016

Thanks, I feel pretty chuffed about finally reaching a year :)

April 21, 2016

This is a good article! But pay attention to the gender of "canzone". Usually verbs, which end on "one" (and not ione!), are masculine, but it is "la canzone" e "le canzoni", not "i canzoni".

April 19, 2016

Whoops-- I'll make the edit!

April 19, 2016

Thanks Mabby, another great explanation!

Another verb that I've found is also pretty funny with its auxiliaries is finire.

  • lui ha finito = he's finished
  • lui è finito = he's dead!
April 21, 2016
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