Example:

Example: This is John.
Method: Figure out which word is the name of a particular person, place or thing and select it.
Answer: John. John is the name of a particular person. Therefore, it is a proper noun.

Example: We bought a pound of carrot.

Example: She walked slowly.
Method: Find the action word and select the word that is describing the action.
Answer: The action word is 'walked' and the word describing it is 'slowly'. Therefore, the answer is 'slowly'.