Most english adverbs ending in -ly have an italian equivalent ending in -mente. To form these kinds of adverbs in English, -ly is attached to the adjective (Usual = usually).
In Italian, mente is attached to the adjective, which must first be changed to the feminine form
solito = solita ---> solitamente (usually)
Raro = rara ---> raramente (rarely)
Most adjectives ending in -e form the adverb by attaching the suffix -mente
felice = felicemente (happily)
veloce = velocemente (quickly or rapidly)
One exception to the previous rule is adjectivesending in -le or -re, which drop the -e before attaching -mente