Is the word plane a common noun?

The word "plane" can be either a common noun or a proper noun, depending on the context.

Common Noun:

* When referring to a flat surface, "plane" is a common noun. For example:

* "The plane of the table was perfectly smooth."

* "The pilot flew the plane through the clouds." (Here, "plane" refers to the aircraft, which is a general type of vehicle.)

Proper Noun:

* When referring to a specific aircraft, "plane" can become a proper noun. For example:

* "The Boeing 747 is a famous plane."

* "The plane landed safely at JFK Airport."

In summary:

* Common noun: "plane" when referring to a flat surface or a general type of aircraft.

* Proper noun: "plane" when referring to a specific aircraft.