Before an adjective, molto means "very" and never changes: molto simpatica, molto simpatici. Before a noun it means "a lot of" or "many" and agrees like any -o adjective: molto tempo, molta pasta, molti amici, molte foto.
Examples
- Mia sorella è molto simpatica.
- My sister is very nice.
- Ho molti amici a Roma.
- I have a lot of friends in Rome.
- Mia nonna ha molte foto.
- My grandmother has a lot of photos.
The mistake to avoid
"Molta simpatica" is wrong: before an adjective molto stays molto.
Where this fits in
Family & people, Italian A1: Talk about your family, say what people are like and how old they are, and introduce your friends.