I've finished reading The Cambridge Grammar of the English Language's small section on verbless clauses (pages 1266–1268), and I want to ask whether certain supplements are considered verbless clauses.
Before that, let's establish what a verbless clause is: a clause whose finite verb has been omitted. Here's an example, with the missing finite verb contained within square brackets:
[1] Dinner [was] over, they resumed their game of chess.
The type of structure I am unsure about is as follows:
[2] He was crying, [he was] obviously sad because of the passing of his father.
This structure omits not only the finite verb, but also the subject. This is not unusual in verbless clauses, but the examples given by CGEL show subjectless verbless clauses being accompanied by either a preposition or subordinating conjunction. See these examples:
[3] He can be very dangerous when [he is] drunk.
[4] The Chinese, whether [they are] drunk or sober, never kiss in public.
Is it fair to categorise example 2 as a verbless clause? I wouldn't call it an adjective phrase because, as far as I'm aware, adjuncts like 'obviously' and those introduced by 'because' don't accompany those types of phrases.