frequently(at frequent intervals) adverb [UK: ˈfriː.kwənt.li] [US: ˈfriː.kwənt.li]There are frequently earthquakes in Japan. = Frecuentemente hay terremotos en Japón.
often(frequently, many times) adverb [UK: ˈɒf.n̩] [US: ˈɔːf.n̩]I often read. = Leo frecuentemente.