What is the example casual preposition?

There's no such thing as a "casual preposition." Prepositions are parts of speech that show the relationship between a noun or pronoun and another word in the sentence.

Examples of prepositions:

* on the table

* in the car

* with my friends

* under the bed

* around the corner

What you might be thinking about is:

* Informal language: Some prepositions are more common in informal speech or writing than others. For example, "like" is often used informally as a preposition, as in "He's like, totally awesome." However, this use is considered grammatically incorrect in formal contexts.

* Prepositions of time and place: Some prepositions specifically indicate time or place. For example:

* Time: *at* 5 o'clock, *during* the summer, *since* last week

* Place: *in* the room, *on* the street, *near* the park

If you can provide more context about what you're looking for, I can give you a more specific answer!