Argument Structure of Observational Verbs and the Eccentric Verb “Help”

Argument structure is a way of categorizing words, especially verbs, in terms of what types of grammatical structures they can connect to. These connections help to complete the meaning of the phrase in various ways. Since different verbs are used to express different types of logical relationships, it’s not surprising that they have different rules about what kind of grammatical connections they can make.

For example, words like “argue”, “know”, “understand”, and “promise” can connect to that-complements. A that-complement is a standalone sentence with the word “that” in front of it.

I know that the treasure is buried on the other side of the island.

The lawyer argued that there was a logical inconsistency in the wording of the law.

Even very young children understand that people like to be treated fairly.

My brother promised that he would return from the war as soon as possible.

As you can see, in every case mentioned above the subclause that occurs after “that” is a complete grammatical sentence that could stand on its own. Here is the sentence parse generated by the Ozora parser:


One important fact about that-complements is that the particle “that” can be ellided. The above sentences can all be rewritten without “that”, and will still be grammatical and also have the same meaning.


(As an aside, it is awkward to write about the word “that” because it is used in so many different ways in English: to introduce that-complements, to link nouns to relative clauses, as a demonstrative pronoun (“that newspaper”), and more).

Another common type of argument structure relates to infinitive complements. These are verb phrases, with no subject, in the standard present tense (dictionary form), that start with the particle “to”. Verbs that express ideas about actions, such as “ask”, “request”, “allow”, and “want”, often take infinitive complements. But if you try to connect a verb that does not accept an infinitive, you get something that is either ungrammatical or strange-sounding:

You really need to take a shower.

The king (asked, ruled**) the knight to rescue the princess.

The new technology will allow us to transmit much more data per second.

The governor (wants, thinks**) to ban smoking in public schools.

Some verbs can take both a direct object and an infinitive complement. These constructions typically express an idea about a person taking an action. In these instances, the object must follow the normal rule about case in English: if you use a pronoun, it must be in the accusative case (him/her/me as opposed to he/she/I). This is pretty natural and doesn’t lead to confusion, because the presence of the particle to clearly indicates that the clause is an infinitive form.

Here are two parse descriptions, illustrating that the Ozora parser “understands” this rule. The red link in the second one is a parse failure indicator, showing that the system doesn’t accept the sentence as grammatical:



Getting to the point of this post, there is a strange category of verbs, which all seem to relate to observation, that allow an odd type of argument structure:

I saw (him/Yo-Yo Ma/he**) play the cello in New York City.

We heard a rock shatter the window.

The paparazzi photographed (her/the actress/she**) swimming naked in a lake.

We lay in the field and watched clouds (meander/meandering/meanders**) across the sky.

A few things to notice here:

  • The particle to does not and in fact cannot appear (try inserting it into the above sentences).
  • There are two possibilities for the tense of the verb: it can be in the standard present (VBP, dictionary form) or the gerund form (-ing suffix, VBG, progressive aspect).
  • There is a noun which is simultaneously the subject of the subclause and the object of the parent clause. But the noun must be conjugated in accusative case.
  • The subclauses are not grammatical on their own, both because the noun is required to be in accusative case, and because the tense of the subclause verb must be VBP or VBG, regardless of the subject.


Him play the cello. **

He played the cello.

I saw him play the cello.

I saw him played the cello**.

Eccentric Verb “Help”

The observational verbs are kind of a strange category, but at least they are a category. It appears that the verb help has a unique argument structure, illustrated as follows:

I helped him (build/building**) his company.

The rain helped wash away the stains on the driveway.

The office staff helped (him/the janitor/he**) clean up the mess.


Actually, there is an easy way to characterize this verb: it takes bare infinitive  argument. A bare infinitive is just an infinitive with the particle to removed. With this qualification, we can analyze help with the same rules we used for the standard infinitive.

Can you think of any other verbs that take bare infinitive arguments?

Writing computer software to analyze English can be frustrating, because it involves a lot of code to handle finicky edge cases. The word “help” is one example: I apparently need to build an entirely new set of grammar rules to accommodate a single word. Another example is the allomorphic word pair “a/an”, which has a special agreement rule that refers to the phonological expression of the word immediately after it (not the head of the noun phrase: “an oak tree” vs “a large oak tree”).





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