It's easy to get into a disagreement over grammar. There is a whole field of study dedicated to disputed grammar. So why does English grammar cause so many arguments? Because there is no final say when it comes to English grammar, the language is constantly changing, and there are many people who simply disagree on various points. The fact that there are now so many unreliable and incomplete sources online only adds to the confusion.
I recently found this website and at first liked the list dedicated to subject and verb agreement. However, when I came to rule number 13, I found it a bit lacking. Here's what rule 13 says:
Rule 13. Sometimes the pronoun who, that, or which is the subject of a verb in the middle of the sentence. The pronouns who, that, and which become singular or plural according to the noun directly in front of them. So, if that noun is singular, use a singular verb. If it is plural, use a plural verb.
Examples: Salma is the scientist who writes/write the reports.
The word in front of who is scientist, which is singular. Therefore, use the singular verb writes.
He is one of the men who does/do the work.
The word in front of who is men, which is plural. Therefore, use the plural verb do.
I agree with the rule to a point. However, it implies that in any situation in which a dependent clause starts with who, which, or that, the relative pronoun will always refer to the noun that comes directly before it. That simply isn't true.
My First E-mail
I sent an e-mail to the owner of the website, Jane Straus. Here's what I said in my e-mail:
Hello Jane,
I found your list of subject and verb agreement rules on your website very concise and helpful. Number 13 especially is one that is usually not included in such lists. However, I believe that the explanation in rule number 13 needs clarification.
I've never read such a strict interpretation of the rule. I've always seen it only in reference to the phrases "one of those people who" or "one of those things that" (or slight variations), which also happens to be the example you use. If that rule were to apply universally, then this sentence, which I found on the front page of a corporate website, would be correct:
"This is a collection of automated tools that enable developers to protect their application code against tampering, reverse engineering and automated attacks."
In fact, I believe that the above sentence is incorrect and "enable" should have an "s." Yet it has a dependent clause starting with "that." If we were to follow rule 13 in this case, then the sentence would be considered correct.
I find that the first sentence in rule 13 is quite vague and could lead to more confusion.
I would love to get some feedback from you on this.
Thanks.
Her Response
While Jane did not respond to me directly, her assistant did. Here's what she had to say:
Jane is unable to answer your query at this time. I have to say that I agree with her regarding its application to your example. I would use "enable," as well. The tools are the objects that enable the users, not the collection. I hope this helps you.
Best wishes,
My Response
I found her response completely unconvincing. So I quickly sent back a reply:
Hello,
Thanks for your response. However, I'm still not convinced.

When a prepositional phrase comes between the subject of a sentence and the verb, the subject still determines whether the verb is singular or plural. The only exception that I've seen is the example Jane used. But I've never seen it applied so broadly as her rule implies and as you're suggesting.
You wouldn't say, "This is a collection that enable developers...."
Nor would you say, "The pile of clothes stink." (Though many people incorrectly do.)
I know the above example is not followed by a dependent clause, but I am trying to demonstrate the basic premise on which I am basing my belief.
The exception that Jane points out has been articulated elsewhere as:
"The phrases 'one of those who' and 'one of the things that' take plural verbs, as in 'The comma splice is one of those errors that always slip past me,' and 'One of the things that drive me nuts is subject-verb agreement.'"
It sounds right, and the explanation makes sense. Yet on Jane's website that rule is explained in a way that applies to so many other examples.
And the explanation that you provided just doesn't wash: "The tools are the objects that enable the users, not the collection."
If that were a valid explanation, then the noun in a prepositional phrase (which is the object of the preposition and not the subject of the sentence) would determine whether a verb is singular or plural in every case.
If there is a valid explanation for applying that rule so broadly, I would love to hear it.
I challenge you to find that rule anywhere else defined so broadly. I've only ever found it explained using the "one of those who" or "one of those things that" phrases (or with slight variations but the same basic construction).
Anyway, I hope you take these messages in the way that they are intended. I love language and grammar and all the related discussions.
Sincerely,
Ken
Jane's Assistant Responds
I found the second response from Jane's assistant similarly inadequate:
Dear Ken,
I think you have your own answer embedded in your query: "The above example is not followed by a dependent clause." You are absolutely correct that in the typical case, the subject of a prepositional phrase, not the object, determines the verb's expression. The key distinction in your original example is the dependent clause.
I hope this helps.
Best wishes,
To Summarize
But she missed the point completely. Rule number 13 on Jane Straus's website is inadequate, and in fact, could lead to incorrect subject and verb agreement usage.
Now that I read the list more closely, I realize that there is no explicit rule to deal with prepositional phrases (except rule 9, which is another exception to the prepositional phrase rule).
Most people who have a decent grasp of grammar know the problems that prepositional phrases can cause for subject and verb agreement. I covered this point in one of my e-mails to Jane's assistant. To reiterate, when a prepositional phrase comes between the subject of a sentence and the verb, the noun in the prepositional phrase does not determine whether the verb is singular or plural. However, as with most "rules" in grammar, there are a few exceptions. Here is my best reading of the exception that I have been discussing here:
When the phrase "one of those people who" or "one of those things that" (or slight variations that follow the same construction) is followed by a dependent clause starting with who, that, or which, the relative pronoun can possibly refer to the noun that immediately precedes it (which is the noun in the prepositional phrase). In that case, the main verb in the sentence will agree with the noun that is part of the prepositional phrase.
(Note: the prepositional phrase within the phrase is "of those people" or "of those things.")
But that is not always the case.
For example, look at these two sentences:
1. He is one of the goalies who actually stops the puck on a regular basis.
2. He is one of the goalies who play on the team.
In the first sentence, the verb "stops" is clearly referring to "one". In the second, "play" clearly refers to the goalies.
So, the most important question to ask in a situation where one of the relevant phrases and the dependent clause with who, that, or which are present is: To which noun is the relative pronoun referring?
Do not adhere to some supposed rule that states that the relative pronoun in such cases always refers to the noun immediately preceding it, because it's not true. In fact, always (heh!) be wary of grammar rules that use the word "always," or "never." There is usually an exception to the rule.
And I'm fairly certain, as I stated earlier, that the sentence I found on the corporate website:
"This is a collection of automated tools that enable developers to protect their application code against tampering, reverse engineering and automated attacks."
is wrong, and "enable" should have an "s."
(Note:in the above sentence, the prepositional phrase is "of automated tools.")
Weigh In
However, I'm still open to interpretations that prove that I am wrong on this. I am constantly learning about grammar and the English language, and updating concepts that I thought I had down cold. When trying to untangle a grammar conundrum, I always ask myself two questions regarding a supposed rule:
Does the usage in the rule's relevant examples sound right?
Does the explanation that backs up the rule make sense?
So, let me know what you think. Who is right about this? Leave a comment or respond to the poll that I have added to the sidebar.