We have currently three tags in our top 20 tags (by amount of questions) that are being arbitrarily and interchangeably used. Those are the highly frequented tags idioms, expressions & phrases. Combined those tags mark a whopping 8,500+ questions. Some 1,300 are tagged with at least two of them.
Even if one looks just at the first page of search results for the tags it is obvious that a lot of idioms questions are not regarding idioms, a lot of phrases questions are not about linguistic phrases and lastly the expressions tag is just all over the place.
Therefore, if one wants to see questions on either of those three topics one has to consider all three of the tags. Thus, making distinguishing between them in the first place completely obsolete.
What can we do about that?
1. Nothing
Plus: Done!
Minus: Searching for any of the tags remains futile
2. A massive and continuous re-tagging effort
What: Keep the tags as they are, re-tag and keep re-tagging
- Plus: One can actually distinguish between the three categories.
- Minus: There are 8,500 questions which would have to be looked at.
- Minus: The three categories seem interchangeably to the usual questioner and likely have to be re-tagged when posted.
- Minus: The effort is massive enough to warrant another minus.
3. The complete merge
What: Merge all tags into one, likely 'expressions'.
- Plus: One tag which holds a clearly defined (big) group of questions.
- Plus: None of the manual effort from the other solutions.
- Plus: A new tag 'grammatical phrases' could give a fresh start for the intention of the old tag phrases
- Minus: One-time mod effort / database solution (idk)
- Minus: All of the previous distinctions are lost (wrong and correct)
4. Merge two, keep one
What: Merging phrases and expressions to expressions; Keep idioms
- Plus: Idioms stay separate from more literal expressions
- Plus: One tag for all colloquial phrases and non-literal expressions
- Plus: No more confusion between colloquial phrases and other expressions
- Plus: Space for a new tag regarding 'grammatical phrases'
- Minus: One-time mod effort / database solution (idk)
- Minus: Continuous effort to keep idioms and expressions apart (which isn't always black and white)