- 6. Same word used as preposition and other parts of speech
- 8. Positions of preposition in the sentence
Many words that we use as prepositions can also be used as adverbs. To recognize the difference in using them, we need to remember that there is a noun or pronoun after the preposition. The noun or pronoun is the object of the preposition. An adverb does not take an object.
In the first sentence above, we have the noun plain coming after the word across (across the plain). The noun plain is the object of the preposition across. The second sentence has the verb swim which doesn't have an object. The word across that comes after the verb is easily recognized as an adverb as it doesn't take an object and it also modifies the verb swim.
For more such words, see List 11 - Prepositions for words used as prepositions or as adverbs.