Because a cycle of lunar phases ________ 29.5 days to complete, it's possible to observe two full moons in a...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

• Because a cycle
• of lunar phases
• [?] 29.5 days to complete,
• it's possible to observe two full moons in a single month,
• one at the beginning and one at the end.

Understanding the Meaning

The sentence starts with a reason:

• 'Because a cycle of lunar phases...'

Now here's where we need to fill in the blank:

• 'a cycle of lunar phases ______ 29.5 days to complete'

Let's look at our choices:

• A. are taking
• B. have taken
• C. take
• D. takes

What do we notice about the subject?

• The subject here is 'a cycle'
  • This is singular - we're talking about one cycle
• 'Of lunar phases' is a descriptive phrase
  • It tells us what kind of cycle, but it's not the subject
  • The word 'phases' (plural) sits right before the blank - this is trying to distract us!
• The verb needs to match 'cycle' (singular), not 'phases'
• We're also describing a general fact about how long these cycles take
  • Not something happening right now
  • Not something that already happened
  • Just a timeless fact

So we need: takes - the singular form that works with 'a cycle' and expresses a general fact.

Now let's read the rest to see the complete picture:

• 'it's possible to observe two full moons in a single month, one at the beginning and one at the end.'

The full meaning is:

• Because a lunar cycle takes 29.5 days (which is less than the 30 or 31 days in most months)
• You can sometimes fit two full moons into a single month
• One full moon at the beginning and another at the end

The correct answer is D. takes

GRAMMAR CONCEPT APPLIED

Subject-Verb Agreement with Intervening Phrases

When a phrase comes between a subject and its verb, you need to identify the true subject and make sure the verb agrees with it - not with other nouns that might appear closer to the verb.

The pattern works like this:

Structure: Subject + [intervening phrase with different number] + Verb

Example 1:

• The box of chocolates sits on the table
• Subject: "box" (singular)
• Intervening phrase: "of chocolates" (plural)
• Verb: "sits" (singular - matches "box")
• NOT: "The box of chocolates sit..."

Example 2:

• The students in the classroom are working quietly
• Subject: "students" (plural)
• Intervening phrase: "in the classroom" (singular)
• Verb: "are" (plural - matches "students")
• NOT: "The students in the classroom is..."

In this question:

• Subject: "a cycle" (singular)
• Intervening phrase: "of lunar phases" (plural)
• Verb: "takes" (singular - matches "cycle")
• The phrase "of lunar phases" is a prepositional phrase (called a prepositional phrase in grammar terms) that describes the cycle but doesn't change the fact that we're talking about one cycle

Why this matters for the SAT: The test often places plural nouns right before the verb to see if you'll mistakenly match the verb to the closer word rather than the true subject. Always identify the core subject first!