La preposizione AT

Le preposizioni in inglese sono una delle aree problematiche per chi vuole padroneggiare questa lingua
Ce ne sono 150
94  composte da una sola parola come at,on,in.....
56 composte da più parole( because of,next to,apart from....)

Ecco cosa dice uno studio
there are several areas of grammar that give Italians trouble, but two of the most important are prepositions and verb tenses.
Italian has many prepositions which are similar to English prepositions, but the two sets do not quite overlaP.EXAMPLE   She is married with him    instead of   She is married to him

The correct prepositions for use with various adjectives and verbs just have to be learned by rote and experience.
(TEFL Problems for Learners in Italy)