I'm not familiar with these technical linguistic terms, but the obvious difference is the use of a preposition in the pseudo-cleft examples, 3 o' clock versus at 3 o' clock, and the kitchen versus in the kitchen - and yet, with the preposition added, the meaning stays the same; this is unusual grammatically. What is also unusual about the pseudo-cleft examples is that, with the preposition added to the noun, you then have a prepositional phrase which functions as a noun, which is unusual grammatically - you don't typically think of a prepositional phrases substituting for nouns.
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