The best replacement for some is any.

The best alternatives to some are rated as following:
★★★★★  any
★★  few
★★  any exercises
★  many
★  somewhat
★  some of
★  learn some
★  several
  any worksheets
  any worksheet
  certain
  none
  little

Your alternative for some is not listed? Suggest!
Speaking about some, one probably shouldn't forget about countable nouns.

Other search terms related to some and their ratings are:
★★★★★ countable nouns
★ some
You have in mind a companion for some and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of some in all years. Click on graph for more.
some
any
few