subject + verb agreement
RuleThe verb agrees in number with the true subject (its head noun), even when other words come between subject and verb.
Curiosity
"The list of items ___ long." is or are? The nearest noun is "items" (plural) — but is that really what counts?
Intuition
Find the head noun of the subject and ignore the modifiers (prepositional phrases) in between. The verb matches the head, not the closest word.
Visualization
See the parts: the head noun (subject) and the verb are highlighted, while the prepositional phrase between them is dimmed. A singular head takes a singular verb.
The verb agrees with the head noun, not the nearest word.
The listof new itemsison your desk
Essence
Watch out: "each/every + noun" is singular; "a number of" is plural but "the number of" is singular; "either A or B" agrees with the nearer noun. TOEIC loves an intervening prepositional phrase as a trap.
Examples
The list of new items is on your desk.
Each of the employees has an ID badge.
The manager, along with two clients, is waiting.
Mini-quiz
"The box of tools ___ in the storage room." Which fits?