How to distinguish prepositions derived from independent parts of speech

Compare sentences: "We ran around the house", "Around the flowers". In the first sentence, "around" is a preposition, in the second, the adverb is in the sentence circumstance of the place. "He came up to me, thanks" and "Thanks to him, my mood has improved." In the first sentence "thanks" is a gerund, the second a preposition.

The noun denotes an object, adjective – characteristic of a subject. Verb – action adverb – a sign of action. All independent parts of speech carry the information load. The preposition performs an indirect role by helping to link words among themselves, and clarifying the nature of this relationship.

To distinguish the preposition derived from independent parts of speech, try to ask the question. If it can be done that means you are an independent part of speech. In the second case, you can ask a question only to that word which is linked to the pretext. By the way, the question itself to contain it. For example, "passed" and "passed". Drove past what? – past the house (preposition). "Past" connects the verb and the noun. Drove where? wide (adverb). Here "by" is a circumstance of the place.

Cross out the word from the text. The exclusion of the preposition clearly violate the text and understand it will be difficult. "After the feast everyone went" transformed into a "Celebration all gone". A noun in the genitive is, as a liaison between it and the verb is not. If to strike an independent word, meaning a little obednitsa, but will continue. "We'll tell you": if you remove the adverb "after", the sentence would sound like "we'll tell you". "I waved to her, but she passed by without noticing". After deletion of the adverb "by" stay "I waved to her, but she passed without noticing". Meaning is stored.