Complex sentence: During 1824--28 Chopin spent his vacations away from Warsaw, at a number of locales; in 1824 and 1825, at Szafarnia, where he was a guest of Dominik Dziewanowski, the father of a schoolmate.
Split into simpler sentences: During 1824--28 Chopin spent his vacations away from Warsaw, at a number of locales. In 1824 and 1825, at Szafarnia, he was a guest of Dominik Dziewanowski, the father of a schoolmate.