GRAMMAR
Noun Clauses
What is a noun clause?
A noun clause (also called  nominal clause) is a dependent clause that plays the role of a noun. A noun clause can function as:
Examples
- What you have done pleased so many fans. (What you have done → subject)
- Whoever comes first will score a point. (Whoever comes first → subject)
- I think  that he is the best match for her. (that he is the best match for her → object)
- You know what you have done. (what you have done → object)