Question 13·Easy·Form, Structure, and Sense
Origami, the art of paper folding, has captivated enthusiasts for centuries. A comprehensive guide containing dozens of intricate diagrams ______ essential for beginners who wish to master the craft.
Which choice completes the text so that it conforms to the conventions of Standard English?
For subject–verb agreement questions, first strip away extra descriptive phrases (such as prepositional phrases and clauses starting with words like "containing," "that," or "which") to isolate the core subject. Decide whether that subject is singular or plural, then pick the verb form that matches in number and fits the time frame of the sentence (general truth = simple present). Read the sentence with your choice to make sure it sounds natural and consistent.
Hints
Find the main subject
Cover up the phrase "containing dozens of intricate diagrams" and read what’s left. What is the main thing the sentence is talking about?
Check singular vs. plural
Once you find the main noun, ask: is it one thing or more than one thing? Your verb must match that.
Check the time of the action
Is the sentence talking about a general, timeless fact, something happening now, or something that happened in the past? Pick the verb form that fits that time.
Step-by-step Explanation
Locate the verb position
The blank comes right before the phrase "essential for beginners." So the missing word must be a form of the verb "to be" that links the subject to the description "essential for beginners." This is called a linking verb.
Identify the true subject
Ignore extra descriptive information. The full subject phrase is "A comprehensive guide containing dozens of intricate diagrams." The core noun here is "guide" (singular). The phrase "containing dozens of intricate diagrams" just describes the guide and does not change the subject’s number.
Decide on number (singular/plural) and tense (time)
Because the subject "guide" is singular, the verb must also be singular. Also, the sentence describes a general truth about guides (what they are like in general), so it should use present tense, not past or a special perfect tense.
Select the verb that matches subject and time
We need a singular present-tense linking verb to match the singular subject "guide" and the general present meaning. The only choice that is singular and present is "is", so the completed sentence should read: "A comprehensive guide containing dozens of intricate diagrams is essential for beginners who wish to master the craft."