In general, it is important to include details in your writing to give your ideas more impact and make your writing more interesting. This is especially important for personal narratives and persuasive essays. (Actually, it's hard to think of a type of writing, aside from perhaps a research paper, that wouldn't benefit from ample but relevant detail).
Why are details so important? For one, your goal as a writer is to create a vivid image in your reader's mind so that your main points are made more forcefully. It is hard to do this with vague information.
Compare the following two samples of writing to see the difference:
(1) Although college is important for many people, it is not absolutely vital in all cases to become success or to reach one's goals. Bill Gates is an excellent example of someone who is not just successful, but also highly accomplished and influential in his field of work. Bill Gates famously dropped out of Harvard College, one of the most prestigious universities on the planet, to found a little software company called Microsoft in the 1970s. At one point, with a fortune of over $40 billion, Gates was the wealthiest human alive. While one could argue that Harvard played a pivotal role in Gates' later success, it is self-evident that the entire four-year undergraduate program at Harvard College was not necessary for Bill Gates.
Okay, now let's look at the same ideas expressed with less detail:
(2) It is not important to complete college in order to be successful. Take Bill Gates as an example. He didn't finish college, and now he is extremely wealthy, even though he doesn't have a college degree. Bill Gates had what it took to be successful, and he didn't need college at all.
Which sounds better to you? (1) of course! Why? Because it has more detail and is more specific. Try to do the same in your own writing as well.
As you know, there are different levels or varieties of formality in language, including in writing and in speaking. (Note: The formality of English that I generally use to explain concepts is less formal than typical academic writing.)
For example, if you were hanging out with your friends, at some point in your conversation, you might say something like, "Yo, wassup? Whatcha thinking of doing today? I got a bunch of stuff I just gotta get done before I go out."
Of course this kind of speech if fine (and expected) for spoken English. But for formal writing, we all learn that we should avoid vague slang and informal language.
Short list of words that are too informal for academic essays
Here's a list of the words I most frequently see in my students' writing that I generally recommend they change:
You can probably guess how to change these words, but let me explain a bit more about each.
Why these words are considered informal
kid literally means juvenile goat (or juvenile sheep). And for some reason in English, we've decided that we should call our young people baby goats. But this doesn't mean we should carry this peculiarity over to our writing. I quite frequently see the word kid used in formal essays to refer to human children. Instead of kid, use child, girl, boy, etc.
mom, dad, grandma, and grandpa should be mother, father, grandmother, and grandfather, respectively. I think that's pretty straightforward–the former set represents the more affectionate language we use with family whereas the latter words are considered more formal.
stuff literally means material used as stuffing, such as what you put inside a pillow. In modern English, we use stuff to refer generally to things or other unspecified material or concepts, both concrete and abstract. But in writing, the word stuff is simply too vague and informal for this meaning.
a lot has several different meanings, such as the lot in drawing lots or a parking lot. We often use the word lot in informal English to mean much or many, which probably comes from the usage of the word lot to refer to a group of items, especially for sale. For example, visit eBay and search for a lot of fidget spinners, and you'll likely find people selling large numbers together. So, instead of a lot, use many, much,a plethora, myriad, etc.
a bunch literally refers to a group of the same kinds of things, such as a bunch of flowers, a bunch of bananas, or a bunch of grapes. In modern American English, we often use bunch to mean many. So, instead of writing that you have a bunch of ideas for how to raise money for the senior prom, just say you have many ideas.
guy is used in the US by most people to refer to men or older boys, and now in modern years, to all members of mixed-sex groups. In formal writing, you'd be better off using boy, teenager, man, etc.
lady sounds like it would be a nice way to refer to a woman, but it's safer just to say woman since lady technically refers to a woman with a certain status in society.
okay is one of my favorite words, and it's one of the best-known and most-used English words worldwide. But it's best used in speech and in informal writing. Try using a more precise word instead, such as acceptable or simply yes.
But how do I know?
Sometimes people aren't aware of which words are considered formal or informal. Fair enough–some of this truly is arbitrary.
One suggestion I've made that seems to help is to imagine which words you'd see on a government (or other) form you'd fill out–in the box where you put in the information about your parents, do you think you'd be more likely to see it labeled "Mother" or "Mom"? What about "Number of children in household" vs. "Number of kids in household"? It would be more common say use "Mother" and "Number of children in household" because this language is considered more formal (as well as more precise).
A few words that I didn't include
I'm keeping a mental list of words that I need to point out sometimes that I don't mention above.
Here's what I have now:
This is just a short list of a small set of words that I see most often in my students' writing. Of course, there are zillions more words that should be avoided as well.
But this list is a good start, and if you can take to heart the logic behind why these words don't quite fit in certain formal essays, you'll be one step closer to being a better writer.
Final note: Sometimes people ask me whether it's acceptable to use informal language when you're quoting the exact speech of someone. Of course! You can't go around changing people's words, so you should in fact (if the situation arises) use the quoted language exactly as it was spoken or written.