Answer:
a. I am now swimming for an hour.
b. he has been playing this guitar since he was seven years old.
c. how long are they discussing?
d. she's been collecting dolls for 3 years
e. the office has been using this machine since 1997.
Answer:
Its - car
This - More and more physicians are beginning to look not just for illnesses but also for patients' habits with long-term health implications
Its - cow
Someone - no antecedent
It - antecedent not clear
Explanation:
The antecedent of a pronoun is the word or phrase whose place the pronoun takes. In some cases, the antecedent is obvious, while in others it's either missing or not clear.
In the first and third sentences, it's simple. In the first sentence, a car's transmission is mentioned. Instead of repeating the word <em>car</em>, we will use the pronoun<em> it</em> and its possessive form <em>its</em><em>.</em> It's the same in the third sentence (cow's tail - its tail).
The second example is interesting because the antecedent of the pronoun <em>this</em> is the entire previous sentence.
In the fourth sentence, the antecedent is missing. We don't know instead of what word the pronoun <em>someone</em> is used.
In the fifth, the antecedent is not clear as the pronoun <em>it </em>could be used to refer to the word <em>rain</em>, or the word <em>mud</em>.
Angela Duckworth was teaching math when she noticed something intriguing: The most successful students weren’t always the ones who displayed a natural aptitude; rather, they displayed something she came to think of as grit. Later, as a graduate student in psychology at the University of Pennsylvania, she defined the term — a combination of passion and perseverance for a singularly important goal — and created a tool to measure it: the “grit scale,” which predicted outcomes like who would graduate from West Point or win the National Spelling Bee. As a result of this work, Dr. Duckworth was named a MacArthur “genius” in 2013, and the notion of grit has become widely known. Her new book, “Grit: The Power of Passion and Perseverance,”
