This is a summary of ways in which (varieties of) English have come to have a separable (or arguably separable) final element -S (pronounced variously as /s z əz/ and spelled variously as S ES ’S), not always with clear semantic content. I’m posting it here for reference in postings to come and as a demonstration of how phonological/orthographic content, like -S, is “just stuff”, with no unified semantic, pragmatic, sociolinguistic, or stylistic value common to all of its occurrences.
This is just an outline, with a few passing comments on some details, though most details (like those concerning alternation or variation between -S and zero) are not covered here; it’s a very complex world.
1. inflectional affixes
1.1. N pl (catsdogshorses)
(including pl-only nouns in –S, like eaves and riches; and pluralia tantum, like scissors and pants)
1.2. N poss (cat’sdog’shorse’s)
1.3. Pronoun independent poss (hersyoursourstheirsits if you can stress it, maybe his)
1.4. V 3sg pres (thinksknowssupposes)
2. “contracted” is/has (Pat’s/Kim’s/Chris’s going, Pat’s/Kim’s/Chris’s already gone)
3. adverbial -S (an old adverbial genitive): always, nowadays, besides; towards, inwards, outwards, backwards, forwards,…; sideways, whiles ‘while’, non-standard anyways, non-standard aways ‘much, far’ (variation between –s and zero for several of these)
4. -S of obscure origin in non-standard a ways: a good/great/little/long ways
5. in clippings (primarily British):
5.1. hypocoristic –S in clipped proper names: Wills (for William), Babs (for Barbara), etc.
5.2. playful adjectival –S with “Oxford –er” (with clipped bases: rugger, footer, soccer): preggers, bonkers, etc. (Wikipedia page here)
5.3. other clippings with –S: maths, turps, meths, etc. (primarily British)
6. nuts ‘crazy, nutty’ (OED thinks this is just pl, but that seems dubious to me)
7. –S in sg nouns:
7.1. [from Gk. neuter pl.] disciplinary: linguistics, mathematics, physics, etc.
7.2. “areas of endeavor”: sports, news, etc.
7.3. names of diseases and conditions: mumps, measles, hives, etc.
7.4. names of games: billiards, checkers, etc.
7.5. the hours of the daily office in the Catholic Church: lauds, matins, nones, vespers
[some of the items in 7.1-5 have variable sg/pl agreement]
7.6. (possible) derivational –S in the history of –nce nouns like dependence
[Stahlke, F.W.; Yonghong Cheng; & Duck-Hee Sung. To appear. English nominalizations in /-s/. Word: Journal of the International Linguistics Society. (puts this case together with the other cases in 7 and the case in 8)]
8. in first elements of compounds: craftsman, spokesperson, etc.
9. contracted us in let’s (Let’s go!)
10. contracted as in non-standard all’s (All’s I know is…), so’s (I did it so’s you’d be happy), seeing’s (Seeing’s how you’re here already,…), being’s (Being’s that you’re here already,…)
11. (non-standard) extensions of wh- expressions (origin unclear, but perhaps by analogy with contractions of wh-words with is and then, sometimes, shifting the –S to the margin of a larger wh-expression or duplicating it at the margin): how’s about, how about’s, how’s about’s; how’s come, how come’s, how’s come’s; what’s about, what about’s, what’s about’s; what’s if; how’s to; what’s else