To further refine your search, you can use additional qualifiers such as score:>0.5. For example, the search score:>=0.5 created:<1y grammar would return only posts mentioning "grammar" that have a score >= 0.5 and were created less than a year ago.
Further help with searching is available in the help center.
Quick hints: tag:tagname, user:xxx, "exact phrase", post_type:xxx, created:<N{d,w,mo,y}, score:>=0.5
