Q: What is a noun clause?
A: The noun clause is a part of a sentence with a subject and a predicate. A predicate is the verb and all the words associated with the verb that tell something about the subject.
A noun clause functions as a noun. Instead of just one word as the noun, there is a set of words (the clause) which act as the noun.
Example: The great thing about working here is that I have a flexible schedule.
What is the noun clause in this sentence? (Hint) it comes after the verb of "be" --> is
The noun clause: that I have a flexible schedule
Also, the word "that" is optional in noun clauses after "be", so technically you could say: "The great thing about working here is I have a flexible schedule." and the noun clause is still the same.
It's very common to use noun clauses when we are commenting about something. For example, the above sentence says "The great thing about working here..." I'm commenting about the things I like concerning my job, such as my flexible schedule. The noun clause tells us what the great thing is about working here.
More sentence examples:
(Remember, the word 'that' is optional in these sentences)
The best part about living here is that I can be close to my family.
The bad thing about staying up too late is that I can't focus at school.
The advantage of making an early reservation is that we can choose the room we want.
One thing I noticed was that Lin made everyone feel comfortable.