Waking with a splitting headache,

[Bassim]

I am wondering if my sentences are grammatically correct.

Waking with a splitting headache, John cursed himself for mixing all kinds of drinks the previous night: wine, beer, gin and brandy. He would need a couple of days until he fully recovered, but the worst all was the prospect of having to listen to his wife endlessly pontificating and telling him off

 

[teechar]

I would use "mixing his drinks" instead of "mixing all kinds of drinks" and "a couple of days to fully recover" instead of "a couple of days until he fully recovered."
Also, you need "worst of all" instead of "the worst all". And don't forget the full stop at the end.

 

[Bassim]

I'll repeat my sentence as an exercise.

Waking with a splitting headache, John cursed himself for mixing his drinks the previous night: wine, beer, gin and brandy. He would need a couple of days to fully recover, but the worst of all was the prospect of having to listen to his wife endlessly pontificating and telling him off.

 

[GoesStation]

A bear is an animal.

 

[Roman55]

Delete 'the' before 'worst'.

 

[Matthew Wai]

Delete 'the' before 'worst'.

Do you mean 'worst of all was the prospect of ...'?
'Worst of all' is adverbial according to Oxford, so how could it be the subject of 'was'?

 

[emsr2d2]

"Best/worst of all" is a shorter way of saying "The best/worst thing of all".

I'm going to be a bridesmaid at my cousin's wedding. I'll have to wear a neon pink dress, ugly shoes and carry flowers I don't like. Worst of all, my outfit includes a green mop cap, making me look like an 18th century parlour maid!

My cousin's wedding is next weekend. My entire family will be there so I'm looking forward to catching up with them. Best of all, I'll get to see my brother for the first time in ten years - he lives in Australia now!

 

[Matthew Wai]

Both 'worst of all' and 'best of all' are adverbial in your sentences, but 'worst of all', according to post #5, would be used as a subject in the OP's sentence.