Complex sentence: At two o'clock a.m. on July 4,1790, Swedish units bombarded Russian shore batteries and Swedish sloops, led by Lieutenant Colonel Jacob Tönningen, attacked a Russian naval unit just west of Vasikansaari Island, west of Björkö sound.
Split into simpler sentences: At two o'clock a.m. on July 4,1790, Swedish units bombarded Russian shore batteries. At the same time, Swedish sloops, led by Lieutenant Colonel Jacob Tönningen, attacked a Russian naval unit just west of Vasikansaari Island, west of Björkö sound.