Here's a breakdown:
Prepositions: Words like "on," "in," "at," "to," "from," "by," "with," etc. They show the relationship between a noun or pronoun and another part of the sentence.
Examples of Phrases with "Double Prepositions":
* "From off the table": This could be shortened to "off the table" or "from the table".
* "On top of that": This could be shortened to "in addition to that" or "besides that".
* "Where is it at?": This is considered informal and incorrect. "Where is it?" is the correct way to say it.
Why they're often considered "bad" grammar:
* Redundancy: The two prepositions can sometimes express the same meaning, making the phrase unnecessary.
* Awkwardness: The close proximity of the prepositions can make the sentence sound unnatural or clunky.
Exceptions:
There are instances where using two prepositions is perfectly acceptable, like:
* Phrasal verbs: "Look up to," "get along with," "put up with," etc.
* Idioms: "From out of the blue," "up to and including," etc.
General advice:
* Be mindful of redundancy: Ask yourself if both prepositions are needed.
* Listen to your ear: If a phrase with double prepositions sounds clunky, try to rephrase it.
* Check for idiomatic exceptions: Sometimes the combination of two prepositions is a standard idiom.
Let me know if you'd like more specific examples or have any other grammatical questions!