What is the adjective clause referring to in these sentences?
1. Preside Harry Truman was one of those people whose middle name is a single letter.
2. Nyos, in Cameroon, is a lake that sometimes releases huge hursts of carbon dioxide from its floor.
I know what the adjective clauses are in each sentence. I just want to know what word(s) these clauses modify.
An adjective clause is a dependent, or subordinate, clause that modifies a noun or a pronoun, and this clause follows the word or words that it modifies. So, identifying the word to which the adjective clause refers is relatively simple because an adjective clause usually begins with a relative pronoun [that, who,whom, whose, which] This relative pronoun has as its antecedent the word that the clause modifies.
Therefore, the easiest way to find the beginning of an adjective clause is to look for the relative pronouns such as that, who, etc. mentioned above. Then, the noun or pronoun that precedes this relative pronoun is the word that the adjective clause modifies.
1. whose is the relative pronoun; the word that the clause modifies is people.
2. that is the relative pronoun which begins the adjective clause; the word the clause modifies is lake.