Using "shì" for noun + adjective + noun Being a beginner, I am bit puzzled by the concept of "shì" being used not for describing nouns with adjectives.

Using search, I think it is clear to me that:


Noun + noun = I can use "shì".
Adjective + noun = I should use "hen".


Well but what I am unable to figure out is the combination, like "This is my new phone".
I am connecting two nouns, but also connecting an adjective and a noun. What rule is the applied?
Seems the answer did not help much, here is mine - it is about predicative and attributive.

My phone is new. The adjective describes the subject, this is the predicative.
My new phone. The adjective is attributive, it is linked to the noun.

If it is predicative, do not use "to be" (shì).

SIDE NOTE: I am a beginner myself and I often see the example "Sky is blue" translated as "Tiānkōng shì lánsè de (天空是蓝色的)". I have no idea why it can be like this as it clearly is predicative.