Io non so niente su di lei.

English Translation

I know nothing about her.

Why is this ‘su di’?


I can’t say, but it’s a common pattern. My observation is that it’s used particularly with personal pronouns, whereas with names you can see su alone: Sai qualcosa su Tom?.


Sono d’accordo @morbrorper. I just accept that “su di” is standard for “about… him/her” and now it comes naturally.


I am also still fighting with that; therefore I like your simple rule.

Can you broaden it a bit?
What if it is followed by “quello/questo/ciò”?

I understand that there is “dI” for other nouns:
“Non so niente di chimica.”

On the other hand, I recently saw a novel “Non so niente di te” and the author had an Italian name.
Is it a slight difference in meanings?


Over to @mike-lima on this one;-)


Uhm, ok, I will try my best but I am not going to have quick and fast rules about everything.

Both “su” and “di” can be used to introduce an argument (“about”).

With “su” used to introduce an argument or topic, I think the topic is normally preceded by an article:

“Non so niente sulla chimica”

If the topic is the name of a person, the article is not allowed:

“Non so niente su Giorgio”.

But if it is followed by a personal pronoun

“Non sai niente su di lei”,

“su di” can be used, "su"can be used as well, but to me it feels like something is missing, or you may use “di”:

“Non sai niente di lei”.

With “di” the situation is easier: you can always use it on its own (although “della chimica” could be used as well).

I couldn’t say using “di” or “su” change the meaning of the sentence. It may be a matter of preference.

“Su questo o quello”… So I think no article is allowed if su is followed by a non-personasl pronoun?


Ottimo spiegazione, grazie. Quite often the rythmn helps me remember; I would find it quite tricky to say “su lei” but ok with “su questo o quello”.

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There’s a good explanation of this topic in “A Reference Grammar of Modern Italian,” second edition, published by Routledge. Below are a few excerpts and examples:

Some prepositions must be followed by di if they govern a personal pronoun from the series me, te, sé, lui, lei, noi, voi, loro: contro di ‘against’; dietro di ‘behind’; entro di ‘within’; presso di ‘by’, ‘at’; sopra di ‘on’, ‘above’; sotto di ‘under’; su di ‘on’,‘about’; verso di ‘towards’:

Su di lei ha letto un libro stampato a Roma.
'She’s read a book about her printed in Rome.’

Other prepositions are only optionally followed by di, when they govern a personal pronoun from the series me, te, sé, lui, lei, noi, voi, loro: e.g., dopo (di) ‘after’, senza (di) ‘without’, tra/fra (di) ‘between’, among.’

È uscito dopo (di) te.
‘He went out after you.’

But note that di is not usually present if the pronoun is in any way modified, or if it is conjoined with another word:

Abito presso loro due.
‘I live with them both.’

Conta su se stesso.
‘He counts on himself.’


Abito presso loro due - thanks for this one in particolare. Hadn’t heard it before.