That’s not uncommon in informal spoken English.
It’s a bit like saying "He was driving real slow." That wouldn’t be particularly unusual either (colloquially).
Many thanks for your quick response. The interesting thing is that this sentence was used to describe a situation. I mean, it was not part of dialog. Why would an author use informal spoken English when he is describing a scene in a story?[YSaerTTEW443543]
I am just getting interested and curious about ‘heavy’. Is there any slight possibility that ‘heavy’ = ‘heavily’ (as an adverb) here? Sorry if it’s totally unrelated.
Yes, in Torsten’s sentence it appears that ‘heavy’ should have been ‘heavily’. The sentence also seems to be in need of some kind of punctuation or the word ‘and’ between ‘heavy’ and ‘seething’. So, it’s also possible that the sentence just has some typos.
My original point was that in informal spoken English, adjectives are sometimes not converted to adverbs, and the adjectives function as adverbs. In my example “He was driving real slow” there are two adjectives that have not been changed to adverbs. In other words, “He was driving real slow” = “He was driving really slowly.”