by RonPurewal Tue Oct 02, 2007 5:19 pm
OK.
In the case where a modifier begins with a RELATIVE PRONOUN (like 'who', 'whose', 'which', and the like), that pronoun usually needs to be placed directly next to the thing it's modifying; in other words, that thing needs to be placed right before the comma.
Prepositions like 'with', however, can refer more abstractly to the action in the sentence, rather than the noun immediately preceding the comma. In the sentence you've cited, 'with arms and legs dangling' is best described as an adverb phrase: a prepositional phrase that modifies 'sleeping'. In general, prepositional phrases - especially adverb phrases like this one - need not necessarily appear right next to the verb they modify; such juxtaposition would often make the sentence sound downright weird (try placing that phrase right next to 'sleeping' and see what happens).
Go back and check the examples in which the modifier goes with the word right next to the comma; the vast majority of them, if not all of them, should involve relative pronouns.