- [Tutor] Let's take
a look at question 36. This is from a passage about fulgurites AKA petrified lightning that forms when a
lightning bolt hits sand. Okay, so question 36 begins here. So I am going to read us in from the beginning of the paragraph. First discovered in 1706,
these formations are found in two varieties, sand fulgurites and the much less common rock fulgurites. As it cools, the silica lining forms a glass walled cavity that may look like a plant's root system. So choice A is no change, and we've gotten apostrophe after the S. Choice B puts the apostrophe
after the T in plants. Choice C has two apostrophes,
one after the T in plants and the other after the S in systems and choice D has an apostrophe
after the M in systems. So all of this tells me that we are looking at a
possessive noun question. We're being asked to identify which noun in the underlined section
needs to show possession, which means we need to
know where the apostrophe or apostrophes are supposed to go. You're likely going to encounter one to two questions like
this on your official SAT. Usually questions like these
will have two nouns underlined and you have to decide whether one, both or neither are
meant to be possessive. So let's review apostrophes
and possession super quickly. A singular noun shows
possession with an apostrophe S as in Amadou's cat. The cat belongs to Amadou.
That's singular possession. For plural possession, we show that a plural noun is possessive by adding just an
apostrophe, no S at the end. As in the cats' tails. Multiple tails, multiple cats. Those tails belong to those multiple cats. So if you're looking
at a phrase that says, Amadou's cat's tails, we know that the apostrophe
placement in cats is wrong unless Amadou has
a cat with multiple tails. So for plural possession, the apostrophe would go after the S. The tails belong to the cats and those cats belong to Amadou. Let's head back to the question. If you want, you can pause the video here and take some time to solve
this question on your own. All right, let's do it together. So what is the sentence saying here? What belongs to what? Okay, so the cavity looks
like a plants' root system. In other words, it looks like
the root system of a plant. So that root system belongs to a plant. So we need to find the choice
that correctly punctuates the idea that this is
a plants' root system. And I said, a plant. The A in a plant tells us it's singular. So we need a singular possessive, that's plant apostrophe S. So that means we've got S apostrophe in choice A, cross that out. And no apostrophe, just
plants in choice D. So we can cross both of those out. And the singular plant would
have a singular root system. We're not talking about
multiple root systems and so that lets us cross out choice C. One plant one root system. And that means we're done. Our answer is choice B. Here's our strategy. For questions like these, you'll need to have a solid
handle on how apostrophes are used to show possession. So first you'll need to
master apostrophe use. And once you've recognized that we're dealing with possession, figure out what belongs to what. Once you've sussed out the
possession side of things, then ask which nouns are
singular and which are plural. And that will help you determine where the apostrophes ought to go. Good luck you've got this.