what is noun in winter is very cold
winter is the noun here .. cold is the adjective and IS is the verb :) :)
WINTER IS NOUN HERE BECAUSE in this sentence winter is the subject.i,e, we are talking about the winter season.
IS is THE VERB.
VERY IS ADVERB OF MANNER OR ADJECTIVE OF FREQUENCY ,because it informs us about the intensity of cold.
COLD IS ADJECTIVE BECAUSE it describes the winter.