The short answer to your question is "mood", like the indicative.
John Lawler comments that "English has no subjunctive mood". I do not entirely agree with him, although I agree with him that in Latin, at least, subjunctive is a mood.
It probably depends on your country and your age! I am aged 64 living in London, UK. Most of the people I talk to in an average week use the subjunctive and use it correctly. But it is probably correct that a majority of native English speakers in the UK no longer use it or use it incorrectly.
50 years ago in the UK, the top schools taught Latin. It was considered to be the best way to learn to write and speak English properly and to learn to think clearly. Today few schools in the UK teach Latin.
When it comes to primary and secondary education (pre-university) in the UK, few children are taught the subjunctive today. But then a significant number of English teachers in the UK are almost illiterate. It is hard to get accurate data on that, because it is a highly contentious issue.
I rarely look at secondary school textbooks, but I do look at "English as a Foreign Language" (EFL) textbooks. The terminology has changed substantially over the last 50 years, which makes your question more difficult. But the EFL books I have seen rarely spend much time dealing with the subjunctive.
John Lawler made an interesting comment below. I should make clear that I am not expressing an opinion on the merits; I am just making the factual point that usage varies substantially even with the UK.
Plenty of academics speaking and writing "perfect" English with RP accents (=Received Pronunciation, still used by the majority of those in senior government positions, the older universities, and in many of the traditional professions) would strongly attack the use of the subjunctive as a needless complexity. They will attack correct spelling, on the basis that in Shakespeare's day, there was no such thing.
It will be interesting to see what happens. Will the internet entrench "correct" English (used, to be pejorative) by the "Establishment", or will we see English fracturing into ever more dialects?
[Sorry, must be getting tired, it took 3 edits to fix those typos]