the likes of which has/have
1)The corporeal, spiritual, emotional, and intellectual sides of human life have all been stirred by the hurricane the likes of which has never been seen in the history of the Earth. From The Vakhtangov Sourcebook by Andrei Malaev-Babel
2)They finally destroy him in a steel works, in a fight to the death the likes of which have seldom been seen on the screen. From Movies of the 90s by Jürgen Müller
"The likes of which" is both followed by have and has, and the result of Google book search is almost a tie.
What is the correct usage?
In the first example, the singular verb "has" is the incorrect conjugation. It disagrees in number with its plural subject, "likes." The second example is the correct one. This time, the plural subject, "likes," is satisfied in number by its verb, "have."
Reading through the responses to your question, I notice that there is confusion as to the identities of the subjects of the verbs "has" and "have." Respondents have offered "hurricane," "fight," or "death" as potential subjects. These are misconceptions. The subject in both sentences is "likes." I'll attempt to break it down.
1)The corporeal, spiritual, emotional, and intellectual sides of human life have all been stirred by the hurricane the likes of which has never been seen in the history of the Earth.
Take a look at this part of the sentence:
"the likes of which has never been seen in the history of the Earth."
This is what is called a genitive relative clause. It’s a relative clause because although it contains a subject (likes) and a verb (has been), its interpretation relies on information in the preceding clause—specifically, the noun "hurricane," to which the pronoun ("which") refers. If we wished to eliminate this dependency, we could rewrite the clause, replacing the pronoun with its target noun (plus article).
The likes of the hurricane has never been seen in the history of the Earth.
As you can see, "the likes of the hurricane" is what is meant by "the likes of which." All we have done so far is to convert a pronoun to a noun. I think that in this construction, it is easier to spot the subject of the clause. Are you beginning to notice the issue with how the verb has been conjugated? If not, don’t worry; there’s more to the explanation.
Let’s focus now on the genitive phrase "the likes of the hurricane." A genitive phrase is used to indicate a relationship between two nouns. In this particular construction, "hurricane" is made to possess "likes" by way of the proposition “of." You may be familiar with another construction of possession formed by adding an ‘s to the end of a noun. For our intents, the two constructions should be interchangeable here. We’ll momentarily convert to the ‘s construction of possession and see if it brings clarity to what is being referenced.
The hurricane’s likes has never been seen in the history of the Earth.
Now, what has never been seen in the history of the Earth? The hurricane? Or its likes (i.e. equals, counterparts)? Its likes have never been seen. If we'd wished to write about the hurricane itself, then we shouldn't have brought its likes into the picture.
So that I'm not accused of having crucially altered the construction of the sentence with this transformation, let's rewind a step and analyze from there.
The likes of the hurricane has never been seen in the history of the Earth.
Again, the likes have never been seen, but that begs the question: “The likes of what?” We cannot leave it at that, so we append descriptive information—“of the hurricane"—clarifying to what the likes belong. It is the likes "of the hurricane" to which we now refer, just as we would the truck of the mailman or the claws of the cat. In no known universe would it be correct to say "The claws of the cat is meowing." It could only be so in a universe the likes of which have never been seen—or perhaps in a universe the like of which has never been seen. Either will do.
The original expression, as can be discerned from Google Ngrams, is the like of which has/have.
In this case, the plurality would have been governed by the original noun.
For example, Google Books yields
landscapes the like of which have never been seen in nature
and
a structure the like of which has never been found in any previous exhibition
At some point around 1950, some people started using likes instead of like. I can see arguments for three possibilities for the correct grammar:
The traditional grammar: likes is colloquial. Use like in formal writing and have the plurality agree with the noun before like. This seems to be the OED's position (they label the likes of as colloq.) but I don't know when the entry was written.
EDIT: upon further examination, responding to a comment it seems like most people use this rule for the plurality, but some people treat the like of as always singular.Use likes and have the plurality agree with the noun before likes. It appears that some people follow this grammar.
Use likes, and always treat it as plural. It appears that some people follow this grammar.
Choose one of these three possibilities and be consistent (assuming that you use the expression more than once in any given piece of writing).
The only possibility I would definitely recommend avoiding is using a plural noun and likes with a singular verb. So don't say, for example:
*Storms the likes of which has never been seen before.
I don't see any examples of this possibility in Google Books.