How do you assign Case to sentences with an infinitival clause?

Look at this example: For the butler to attack the robber would be surprising.

Here, the butler and the robber are assigned accusative case. Is 'for' assigning case to the butler and 'to attack' assigning case to the robber? Doesn't there need to be a subject in the clause, so there's something with nominative case?

Am I right in saying 'to attack' does not assign the nominative case to anything?

For sentences such as: 'That the butler attacked the robber is surprising.' I understand the case assigning, attacked assigns nom. to the butler and acc. to the robber. As soon as an infinitival clause gets involved, I find myself getting very confused. Can anyone help?

Solution 1:

Common nouns in English have no nominative or accusative contrast and are said to be plain case. Pronouns on the other hand may be nominative, accusative or genitive.

The default case for pronouns in English is the accusative, not the nominative. Nominative case pronouns, as a general rule, only occur as the Subjects of finite clauses—in other words only when they are the Subject of a clause with a tensed verb or are part of a subjunctive construction:

She exists.

The doctor recommended she be sent to the hospital immediately.

In rather pedantic styles of English, nominative case may also be used for pronouns functioning as Complements of the verb BE:

A: Who's there?

B: It is I

Nominative case is not used for pronouns functioning as Subjects of non-finite clauses in English:

• We arranged for her to be sent to the hospital.
• We approve of his being appointed Managing Director.
• I don't like him doing that.

The Original Poster's sentence uses an infinitival clause as the Subject of the larger sentence. Because this clause has no tense the Subject cannot be in the nominative.