Today's tip:定语从句前的停顿

讲座中出现的一些词：
adjective clause 定语从句
in passing 顺便地

Welcome to Daily Tips on Learning English. Today’s tip is on when to use pauses before adjective clauses.
Let’s take an example. In the sentence “My sister who lives in San Francisco is a doctor”, the adjective clause is “who lives in San Francisco”. It describes my “sister”. There’s no pause before the adjective clause. So, it means that I have more than one sister, and the one who lives in San Francisco is doctor. There’s a pause after an adjective clause because it is a long sentence. But there can be no pause in the group of words “my sister who lives in San Francisco”. Because this is one idea or thought group. Listen to the sentence again. “My sister who lives in San Francisco is a doctor.” The same words used in that sentence have a different meaning if there’s a pause before the adjective clause “who lives in San Francisco”. Listen to the new sentence. “My sister, who lives in San Francisco, is a doctor.” Now there’s a pause before, and a pause after the adjective clause, and in writing, there now is a comma before and a comma after the adjective clause. This sentence means that I have only one sister. She is a doctor, and by the way, she lives in San Francisco. The information conveyed by who lives in San Francisco is not necessary to understand whom I am talking about, as I only have one sister. I just added it in passing.
If you say,“My girl friend who drives a BMW is a good dancer.”You’re saying that you have more than one girl friend. “My boss who is very generous gives me a raise every year”means I have more than one boss.“Hawaii which is an island in the Pacific is a poplar tourist spot”means there’s another Hawaii not in the Pacific. So remember to pause before and after adjective clauses only when it is referring to something or someone of which there’s only one.
This has been today’s daily tip on learning English.

Answer:
1）My sister who lives in San Francisco is a doctor.
I have more than one sister, and the one who lives in San Francisco is doctor.
2）My sister, who lives in San Francisco, is a doctor
I have only one sister. She is a doctor, and by the way, she lives in San Francisco.