Complex sentence: From 1998 to 2006, Vänsterpartiet was in an arrangement with the ruling Social Democrats and the Greens and until 2006 supported the Social Democratic minority government in the Swedish parliament, as well as in many of Sweden's counties and municipalities.
Split into simpler sentences: From 1998 to 2006, Vänsterpartiet was in an arrangement with the ruling Social Democrats and the Greens. Until then it also supported the Social Democratic minority government in the Swedish parliament, as well as in many of Sweden's counties and municipalities.