CI e NE

The words ci (vi) and ne can be used as both adverbs and pronouns. They are normally positioned before the inflected verb, but after the infinitive, certain imperatives, the gerund and the participle. As an adverb of place with the meaning ‘here/there’, ci is frequently used with verbs like andare, venire, essere, abitare:
Ci vengo, ci vado - I come here, I go there
C’è, ci sono - there is, there are
Mi piace Bologna. Ci abito da tre anni - I like Bologna. I've lived there for three years

When talking about presence or availability you may also use the verb avere, often combined with ci, that changes into ce before the direct pronouns lo, la, li, le:
Hai una mappa di Bologna? Sì, ce l’ho. - Have you got a map of Bologna? Yes, I've got it

Ci is also used in idiomatic expressions with the verbs mettere and volere:
Per arrivare a Bologna ci metto un’ora. - You take one hour to get to Bologna
Ci vuole molta pazienza! - You need to be patient!

Used as a pronoun, ci can replace both ‘a + noun’ and ‘a + verb’ phrases:
Penso sempre alle vacanze. Ci penso sempre. - I always think about holidays. I always think about it
Lisa prova a ballare ma non ci riesce. - Lisa tries to dance but she is not able to

The word ne, used as an adverb of place means ‘from here/from there’:
Me ne vado - I'm leaving

From the locative meaning stems quite naturally the partitive uses of the pronoun ne:
Vuoi del vino? Sì, ne prendo un bicchiere - Do you want some wine? Yes, I'll have a glass
Conoscete dei ragazzi italiani? No, non ne conosciamo - Do you know any Italian guys? No, we don't

Used as a pronoun, ne can replace ‘di + noun’ phrases:
Giulia non parla mai del suo lavoro. Giulia non ne parla mai. - Giulia never talks about her job. Giulia never talks about it