A simple noun is one word that names a place, person, thing or idea, examples: fish, tooth, brush, hand, bag, fairy.
On the other hand, a compound noun is a noun which is made by combining or compounding two or more simple nouns or words.
A compound noun may be made up of two or more words which stand separately, but still name just one person, place thing or idea, examples: bus stop, full moon.
A compound noun may be made up of two or more simple nouns which are joined to make a new word, examples: handbag, football, toothbrush.
A compound noun may be made up of two or more words which are connected with a hyphen, examples: runner-up, round-trip, mother-in-law.
The compound noun may also be made of two simple nouns joined with the conjunction and.
In this case, the nouns, once separate in themselves, are now conceptualized as one.
- Bread and butter is a delicious snack.
In the above sentence, “bread” and “butter” are fused as one thing. The idea is that bread by itself or butter by itself is not a delicious snack. What is a delicious snack is “bread and butter” when combined or fused with each other.
Therefore, the two nouns “bread and butter” are conceptualized as one compound noun in the sentence “bread and butter is a delicious snack.”
However, they are two simple nouns in a sentence such as:
Bread and butter are two common breakfast ingredients.