No, the word 'early' is not a noun; early is an adjective (describes a noun) or an adverb (describes a verb or an adjective). Example uses:
Adjective: We can see the early movie before we eat.
Adverb: If we leave early we will miss the crowd.
Yes a proper noun can be the subject of a sentence. eg John left home early this morning. -- John is the proper noun.
No, "early childhood" is a common noun. It refers to the time period of a child's life from birth to around age 8.
The common noun is test. The only other noun in the sentence is Jamal, which is a proper noun.
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Pencil proper or common noun
No, except at the beginning of a sentence because it is not a proper noun.
"Pangaea" is a proper noun. It refers to the supercontinent that existed during the late Paleozoic and early Mesozoic eras.
proper noun
Exxon is a proper noun
Yes, the word 'Ali' is a proper noun, the name of a person.A proper noun is the name or title of a specific person, place, or thing.A proper noun is always capitalized.
proper noun
Proper noun