The first official grammar-related post I would like to make is on the topic of phrasal verbs. I learned about these for the first time while teaching ESL, and the knowledge not only revolutionised my life but also solved a problem for me I previously had not been able to overcome.
I am frequently dismayed by the lack of writing and grammar instruction in schools these days. Still, everyone seems to know that you should never end a sentence with a preposition. However, I've seen some debate that you can end a sentence with a preposition on some occasions. Take, for example, the following sentence:
I'm going to Bob's to cheer him up.
I certainly couldn't say:
I'm going to Bob's up which to cheer him.
The only way that sentence works is in the first instance. As a result, people think that you are ending the sentence with a preposition. However, in this case, "up" does not function as a preposition because it's part of what's called a "phrasal verb."
The phrasal verb is intuitive based on its own name: a phrase that's a verb. More specifically, it's a verb + preposition or adverb that changes the meaning of the verb. For example:
I fell down the stairs.
I fell in love with someone.
Clearly, the action of falling does not mean the same thing both cases.
One could argue that in my first example, I could go to cheer up Bob, and then I wouldn't be ending my sentence with a preposition, but the point here is that once the preposition or adverb is added to the verb, it functions as part of the verb structure and not as an independent preposition or adverb.
I had always tried to figure out how not to end some of my sentences with prepositions; when I learned about phrasal verbs, I realised why I was unable to prevent myself from fixing that problem. If you have a burning need to find out more detailed information about phrasal verbs, please ask, but this is the simple explanation.