It seems we can achieve a consensus on a certain set of tags this time without reading too much into things. Let's clean up sentence-related tags. I just came up with a few ideas, and I present them in separate meta posts so we could discuss each of them.
syntax is more general, more correct, and can replace grammar more effectively where it should. After the synonymizing, people would still be able to tag their question as "sentence-construction", it's just that the tag name would show as syntax, so there isn't a "learner can't choose" argument here.
What do you think?