Most often, the word class is a noun. example: He teaches the fifth grade class.
In the following sentence, class is an adjective:
Our class project won first place.
The word class describes the project. Therefore, it is an adjective.
it is an English speech
Course is a noun. It refers to a direction or class.
A noun: He is in my class. A verb: to class (classed).
a great big gorilla
onomatopoeia
Takes is a verb in that sentence.
conjunction
Course is a noun. It refers to a direction or class.
Noun. However you could class it as a adjective in the case of 'cobalt blue'.
No. adjectives are the third largest class of words in English.
If you mean the part of speech, it is a noun. If you mean the etymology, it comes from Greek.
It depends on the context. It can be a verb, as in "Please excuse me," or a noun, as in "The student handed in his excuse for missing class."