Give yourself 45 seconds and see if you can solve the following question.
You might have been tempted to pick (A). But wait a sec…only one of the redwoods has the largest trunk diameter. So that is fine. (C) might sound weird but “uses” is simply the second verb (“includes…uses”). (D) is fine because “itself” is used as a reflexive pronoun adding emphasis to trunk.
The problem is with the “it”. What does “it” refer to? Well, “it” should refer to a clear noun. Instead, we have this long subject beginning with the gerund: “determining”. But, it’d be weird to consider that gerund as the noun that can be used in place of “it” (just try plugging in “determining” in place of “it”).
Instead “it” should be replaced by “doing so”, which refers to the phrase beginning with a gerund and which doesn’t include a noun that “it” could legitimately refer to. That’s a mouthful, so let me give an example.
Correct: Doing homework on time is difficult since it requires lots of effort.
Correct: Doing homework on time is difficult since doing so requires lots of effort.
The “it” could refer to homework, so that is fine (just substitute homework for “it”).
The second sentence is also fine, since “doing so” stands in for the phrase “doing homework”. Again, plug in “doing homework” in place of “doing so” and everything should sound fine. Now let’s take a look at a slightly different sentence.
Incorrect: Finishing in first place is tough since it requires lots of practice.
Correct: Finishing in first place is tough since doing so requires lots of practice.
It would be weird to say: finishing in first place is tough since first place requires lots of practice. Similarly, saying that finishing in first place is tough since finishing requires lots of practice isn’t what you’re going for either. It’s the idea of “finishing in first place”, which cannot be easily whittled down to “it”, that must be described by the phrase “doing so”.
Finally, if you have a gerund that is not part of a larger phrase, say “swimming”, then “it” can be used to refer to it.
Correct: Swimming is tough since it requires daily practice.
It’s only when you have a phrase that follows the gerund that you can’t substitute “it”, but must use “doing so”.
Check out all of these tips in this week’s video here:
If you have any questions for me, leave them in the comment box below! 🙂