Grammar Noun Clauses Beginning with That A noun clause is a dependent clause that is used to make a statement within a statement.These sentences usually begin with it. Common that begin sentences with noun clauses as the subjects include It is a fact (that) It is funny (that) It is obvious (that) It is possible (that) It is strange (that) It is surprising (that) It is surprising (that) toothbrushes only became common in the 20th century.