Use reduced adjective clause correctly
Adjective clauses can appear in a reduced form. In the reduced form, the adjective clause connector and the be-verb that directly follow it are omitted.
- The woman who is waving to use is the tour guide.
- The letter which was written last week arrived today.
- The pitcher that is on the table is full of iced tea.
Each of these sentences may be used in the complete form or in the reduced form. In the reduced form the connector who, which, or that is omitted along with the be-verb is or was.
If there in no be-verb in the adjective clause, it is still possible to have a reduced form. When there is no be-verb in the adjective clause, the connector is omitted and the verb is changed into the -ing form.
- I don’t understand the article which appears tin today’s paper [-->appearing]
In this example there is no be-verb in the adjective clause which appears in today’s paper, so the connector which is omitted and the main verb appears is changed to the -ing form appearing.
It should be noted that not all adjective clauses can appear in a reduced form. An adjective clause can appear in a reduced form only if the adjective clause connector is followed directly by a verb. In other words, an adjective clause can only be reduced if the connector is also a subject.
The woman that I just met is the tour guide. [does not reduce]
The letter which you sent me arrived yesterday [does not reduce]
In these two example the adjective clauses cannot be reduced because the adjective clause connector that and which are not directly followed by verbs, that is directly followed by the subject I, and which is directly followed by the subject you.
A final point to note is that some adjective clauses are set off from the rest of the sentence with commas, and these adjective clause can also be reduced. In addition, when an adjective clause is set off with commas, the reduced adjective clause can appear at the front of the sentence.
- The White House, which is located in Washington, is the home of the president.
- The White House, located in Washington, is the home of the president.
- Located in Washington, the White House is the home of the president
- The president, who is now preparing to give a speech, is meeting with his advisors.
- The president, now preparing to give a speech, is meeting with his advisors.
- Now preparing to give a speech, the president is meeting with his advisors.
Source: Longman Complete course for the TOEFL test