Scientists examining the migration patterns of monarch butterflies across North America have discovered that the timing of each colony's departure,...

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

• Scientists examining the migration patterns of monarch butterflies across North America
    • have discovered that
        • the timing of each colony's departure,
            • despite the variations in weather conditions and food availability
            • across different regions,
        • _____ remarkably consistent.

Understanding the Meaning

Let's start reading from the beginning:

Scientists have been examining monarch butterfly migration patterns, and they've discovered something interesting.

What did they discover?

• They discovered something about 'the timing of each colony's departure'
  • So the discovery is about THE TIMING - when each colony leaves

The sentence continues:

• 'despite the variations in weather conditions and food availability across different regions'
  • This phrase starting with "despite" gives us context
  • It's telling us: even though weather and food vary a lot from place to place...

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

• 'the timing... _____ remarkably consistent'

Let's look at our choices:

• We're deciding between: is / are / were / have been
• This tells us we need to pick the right verb form

So what verb do we need? Let's identify what it needs to match:

• The subject doing the action (or being described) is: 'the timing'
  • "The timing" is what "is" or "are" consistent

• Between "the timing" and our blank, there's a lot of extra information:
  • 'of each colony's departure' - describes which timing
  • 'despite the variations...' - provides context
  • These phrases contain words like "variations" (plural) and "regions" (plural)

But what do we notice about the structure here?

• Those plural words are inside descriptive phrases
  • They're giving us extra details

• The actual subject - the thing being described as consistent - is: 'the timing'
  • "The timing" is singular (one timing, not multiple timings)

So we need: is - the singular verb that matches "the timing."

The complete meaning is:

• Scientists discovered that the timing of when colonies leave is remarkably consistent, even though conditions vary a lot from place to place.

GRAMMAR CONCEPT APPLIED

Subject-Verb Agreement with Intervening Phrases

The key to subject-verb agreement questions is identifying the true subject, even when it's separated from the verb by long descriptive phrases. Here's the pattern:

The core structure:

• Subject + [intervening phrases] + Verb
• The verb must agree with the subject, NOT with nouns in the intervening phrases

Example 1:

• The collection of rare stamps is valuable.
  • Subject: "collection" (singular)
  • Intervening phrase: "of rare stamps"
  • Verb: "is" (singular, matches "collection")
  • NOT "are" - even though "stamps" is plural

Example 2:

• The effects of the new policy are unclear.
  • Subject: "effects" (plural)
  • Intervening phrase: "of the new policy"
  • Verb: "are" (plural, matches "effects")
  • NOT "is" - even though "policy" is singular

In this question:

• Subject: "the timing" (singular)
• Intervening phrases: "of each colony's departure" + "despite the variations in weather conditions and food availability across different regions"
• These phrases contain plural nouns ("variations," "conditions," "regions")
• But the verb must match the subject: "the timing is" (singular)

Strategy tip: When you see a long gap between subject and verb, mentally cross out the descriptive phrases and read just the core: "the timing _____ consistent" → "the timing is consistent."