Depends on the situation! For me it’s grammatical in most informal texts, e.g. emails. (Also, the first sentence of this paragraph.)
> Second, there's more than just the subject missing in "Former emergency response driver...".
This is a good point; I did indeed miss this subtlety. (Actually, it’s not even very subtle!) In this case, I must admit to being unsure about how to analyse this.
Huh, interesting — thanks for the pointer! I’ve been wondering about this for a while. Do you happen to have any more resources? (I enjoy linguistics, but haven’t really read much about syntax; my favourite topic is morphosyntactic alignment.)
It’s hard to find any good scholarly references on the differences between pro drop and diary drop (I guess because they are uncontroversial and not particularly subtle). However, section 4.2.1 of this MA dissertation has a decent, though very brief, summary: https://awweir.files.wordpress.com/2017/04/weir-ug-diss.pdf Similar observations are also made in the following paper: https://core.ac.uk/download/pdf/76381796.pdf
Depends on the situation! For me it’s grammatical in most informal texts, e.g. emails. (Also, the first sentence of this paragraph.)
> Second, there's more than just the subject missing in "Former emergency response driver...".
This is a good point; I did indeed miss this subtlety. (Actually, it’s not even very subtle!) In this case, I must admit to being unsure about how to analyse this.