the definition of "wont" as a noun from britannica.com:
wont - (old-fashioned) a usual habit or way of behaving:
He enjoyed a drink after work, as is his wont ( = as he usually or often does).
(1a) He enjoyed a drink after work, as is his wont.
Could you tell me please:
how the as-clause is made;
why "as is his wont" means "as he usually/often does";
why there is "is" in the as-clause;
why this "is" is grammatical?
What will be if we replace "is" with "did" or "does"?:
(1b) He enjoyed a drink after work, as does his wont.
(1c) He enjoyed a drink after work, as did his wont.
my sentences:
(2a) His grandfather enjoyed a drink after work, as does he now. - I know it's correct
(2b) His grandfather enjoyed a drink after work, as is he now. - I know it's incorrect
Proceeding from (2b), (1a) must be incorrect too. Why is it not so?