Question: > 
> 1. Professor required his students to return their papers typed.
> 
> 
> 

vs

> 
> 2. Professor required that his students return their papers typed.
> 
> 
> 

Which of the examples is correct? Do they have the same meaning?
What is the preferred usage?

<http://oxfordlearnersdictionaries.com/us/definition/english/require> and <http://www.thefreedictionary.com/require> do not mention any usage differences

Answer: 
Require is a transitive verb, which means that in either case, we can look for an object later in the sentence. In the first sentence,

> 
> Professor required his students to return their papers typed.
> 
> 
> 

We can diagram everything after "required",

> 
> his students to return their papers typed
> 
> 
> 

as part of the object phrase, which in this case is an infinitive phrase functioning as a noun. The base infinitive is "to return," and we can add the object to expand the infinitive phrase, "to return their papers," and add an adverb (or postpositional adjective, but dynamically here it's probably just an adverb) to make it "to return their papers typed." But you can still go further. Since this infinitive form doesn't have an explicit subject, you can add the subject, "his students to return their papers typed." In fact, this verb, "require," happens to require infinitive objects to have an explicit subject. This is because in the absence of an explicit subject, the subject is assumed to be the subject of the clause. For example,

> 
> Professor wanted to return their papers typed.
> 
> 
> 

In this sentence, since "his students" is not included as the explicit subject, the implicit subject for the infinitive phrase must be "professor."

The object of the sentence can also be a relative clause (signaled by "that") as in

> 
> Professor required that his students return their papers typed.
> 
> 
> 

In this case, the object, what the professor required, is in the relative clause. Just about anything is acceptable as long as the phrase signaled by "that" is an independent clause in the subjunctive mood. You could even drop the word "that" and it would still be correct in some contexts.

My conclusion is that both of these sentences are perfectly acceptable in English. Hope that helps.
Both of these sentences are attempting to get at the same semantic meaning, and in my opinion, both are grammatically incorrect. Both are good examples of English speakers' generally woeful failure to understand the subjunctive and infinitive moods.

The first sentence should be thus:

> 
> Professor required his students return their papers typed.
> 
> 
> 

The "to" is totally superfluous. In this sentence, "return" is in the infinitive mood. Verbs are in the infinitive mood if they are being used as part of a noun phrase following the main verb of the sentence, which in this case, is the past-tense "required".

The second sentence should be thus:

> 
> Professor required that his students return their papers typed.
> 
> 
> 

OK, you got that right here - the verb "return" is in the subjunctive mood, indicating a hypothetical or possible scenario, but not one that is necessarily true, or happening right now. However, your question title provides an example of where this is missed, where you say:

> 
> to require that someone does something
> 
> 
> 

This is grammatically incorrect. You require that someone *do* something, not *does*. *Does* is present tense, intended to indicate that something is a fact. As you are requiring that something be done, it is not (necessarily) yet a fact, and so the subjunctive mood *do* is appropriate:

> 
> to require that someone do something
> 
> 
> 

Note that in English, the subjunctive form is *always* identical to the infinitive form of a verb. For that reason, I sometimes call it the "subfinitive" form.