| All prepositional verbs take prepositional objects. |
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True. But what do we do with ambi-structural "looked after"?
They looked [after the sheep] (DO)
They looked after [the sheep] (DO)
What evidence is there that speakers don't parse "look after" as a unit and "the sheep" as its direct object? It seems all too neat 'n tidy to lump verbs of phrase into two categories.
The distinction between phrasal verbs and prepositional verbs is based on modification, or rather determining whether the bits that follow the verb are an integral part of the verb's meaning (i.e., DO) or modification (i.e., Adverb). Going back to our example "after the sheep", it definitely does not function as an adverb; it's an object of some sort, we know that, and whether it's a DO or the O of P doesn't seem to matter all that much with regards to meaning. O is required by P. If P is an integral part of V, then O, by proximity alone functions as part of P. In other words, structurally, the noun "the sheep" functions as the object of the preposition "after", but, and in terms of semantics, its contribution is ambi-structural. It goes both ways. The line between "looked" and "after" is fuzzy. Are they one semantic unit or are they two? It's a nano distinction.
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Prepositional verbs are verbs such as abide by in (7), refer to in (8), glance at, lean against, account for, reply to, absolve from, long for, yearn for, argue about, and defer to in which the P with the NP functions as an object:
7. They abided
by the contract.
8. He referred
to that article.
These verbs require a PP, i.e. (9) and (10) are ungrammatical, and that's why the PP is considered an object rather than an adverbial.
9. *He abides.
10. *He refers all the time.
SOURCE:
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