Anyone writing for an academic class needs to know the standard expectations for writing in that subject's style. For example, a paper for a history assignment is somewhat different from one for English class.
Formal English writing, that is, the type used for composing essays, has certain rules and don'ts which, when a writer is fully aware of them, make it easier for the student to create papers that meet the mark.
In fact, if you remove, replace, or avoid constructions with the following words or elements, you automatically write more formally, and can then focus mainly on smoothness and clear content:
Rules of organization:
Clear statement of your overall idea
One subtopic per paragraph
Specific examples, instances, proof, and evidence
The expectation that the reader is reasonably intelligent
"Don'ts" in choosing language and punctuation:
No contractions ("Do not use 'don't.'")
No exclamation marks or question marks (enough said!!)
No slashes or dashes (these are not part of formal writing--for now)
Avoid Nasty No-No's:
you (second person pronoun, all forms)
mom, dad, kid, guy
a lot, lots, cute
fun, funny, stuff
get, got, gotten
These words and phrases suffer from one or more of the following problems. They are either too casual (colloquial language), too vague, or too frequently used. One need only look up "thing" in the dictionary to discover that it can stand for any noun. That is a powerful example of its lack of specificity. (Just so you know, something, nothing, anything, and everything are words that work well and have meaning in their context. Use them!)
Having stated all these strict guidelines, I want you to remember this: you write various documents for various purposes. Just because these elements are not acceptable in an essay doesn't mean you can't use them at all. They work fine in an email or when talking with others. Simply avoid them if you are writing for a school subject.
Next: the concept of skeleton (woooh! spooky!!)