Italian to english translation. Please.?

What is the difference in these structures.

1) Ho Mangiato

2) Io Mangavo

3) Avendo Mangiato.



If needed please make them in a sentence.

Thankyou, grazieItalian to english translation. Please.?
There is a mistake.. Io mangiavo ( inperfect tense) verb to eat (mangiare)

** 1) Yesterday I have eaten a cake ..* Ieri ho mangiato una torta**

**2) while I was eating an ice-cream arrived a friend of mine

...." mentre mangiavo un gelato arriv貌 un mio amico"

** avendo mangiato is "gerundio tens"

* having eaten a lot I finished in hospital** Avendo mangiato molto finii in ospedale "

Ever ready to help in italian language..by.by from Francis - ItalyItalian to english translation. Please.?
apparently it means

I Mangiato

I Mangavo

Having Mangiato



hope it helpsItalian to english translation. Please.?
ho is to have

io is i

avendo is having