- perfect(0 followers, 82 questions) and perfect-aspect (0 followers, 54 questions) should be merged in some way. I'm not sure what it should be named; on the one hand, "perfect" is ambiguous as a tag name, but on the other hand, there are differing views on whether the English perfect is an "aspect" or a "relative tense."
See also this post from tchrist (way back in Jan 2014!): The Great ELU Tag Clean-up Proposal of 2014
Edit Oct 16, 2015: As has been previously discussed on the overall Stack Exchange meta site, the procedure for the community to process tag synonyms is pretty broken for small tags. For this reason, I'd like to repeat my previous request for a moderator to take action and make some of these synonyms. This post received 3 upvotes and 0 downvotes; tchrist's post that I linked has 21 upvotes and 0 downvotes. I've left this post up for a while, and nobody has objected to any of these proposed synonyms. Besides this edit, I'm also going to try to contact a moderator in chat.
Former suggestions that have now been implemented:
passive(0 followers, 58 questions) should be made a synonym of passive-voice (2 followers, 192 questions). Completed.progressive(0 followers, 14 questions) should be made a synonym of progressive-aspect (0 followers, 103 questions). Completed.subject-verb-agreement (1 follower, 55 questions) should be made a synonym of verb-agreement(2 followers, 403 questions). Basically all verb agreement in English is with the subject (Araucaria pointed out one exception, proximity concord, that seems pretty marginal to me), so these tags have a huge amount of overlap. Everything in subject-verb-agreement should safely fall under the category of "verb-agreement" as a whole.Completed.