Having a good handle on the English language is not only good for you, it’s good for your career. Sure, everyone makes mistakes – especially typos (just ask me!) – but simple errors can make you look bad.
If you want to look your best, you have to use proper English. It’s also a good idea to have someone read over anything really important. And never, ever let instant messaging shorthand enter professional correspondence.
Here are 17 common mistakes that you should avoid.

Fewer and Less
Which do you use when?
To keep it simple, the Plain English Campaign says that you should use fewer when you mean not as many and less when you mean not as much.
Examples:
"I have fewer than 5 wigs."
"I would like less headcheese."

Vice-A-Versa
No, no, a thousand times no! It's vice versa!

Then and Than
Use then when you're talking about time, use than when you're comparing things.
Examples:
"First you do this, then you do that!"
"I think my car is faster than your car."

Expresso
If you order an expresso at a real coffee shop you're likely to get stink eye from your barista. It's espresso with an s.

Ironic
Even after all this time, people still mess up irony and ironic.
Here's the Merriam-Webster definition:
- the use of words that mean the opposite of what you really think especially in order to be funny
- a situation that is strange or funny because things happen in a way that seems to be the opposite of what you expected
Pay attention: A black fly in your Chardonnay is not ironic. It's a drag.
Whereas a firehall burning down is ironic.

Bemused
Many people think that bemused means amused. Nope.
Bemused means to confuse or bewilder someone.
Example:
"Pat's request for bacon-flavoured ice cream bemused the waiter."

Literally
Literally means exactly as stated, not exaggerated.
Example:
"My head literally exploded when Sally gave me bacon-flavoured ice cream!"
In this example, you're saying that your head actually exploded, leaving Sally to clean up the mess.

Lose and Loose
Lose means no longer having something, to be deprived of or failing to win.
“I better not lose any more weight.”
Loose means not in a fixed place or poorly fitting.
"This bacon-flavoured ice cream diet must be working, look how loose my pants are!"

Supposably
NOT A WORD!
You probably mean supposedly.

For All Intensive Purposes
Here's another phrase that many people mangle.
It's actually for all intents and purposes.

It’s and Its
It's is a contraction of it is or it has.
Example:
"It's going to rain."
Whereas its is the possessive form of it.
"He picked that hotel because of its pool."

I Could Care Less
Saying I could care less doesn't mean you don't care at all, it actually means you care a little. Aww!

Your, You’re and Yore
Your refers to something the person you're speaking to possesses.
"Is that your car?"
You're is a contraction of you are.
"You're in trouble!"
Yore is long ago.
"This story is about a princess in the days of yore."

Sherbert
If you're talking about the frozen treat, that would be sherbet. Sherbert is not a word.

They’re, Their and There
They're is contraction of they are.
"They're the brightest and the best."
Their shows possession.
"It's their car."
There refers to being in or at a place or position.
"She's sitting over there."

A lot, Alot and Allot
A lot can mean a large amount.
"I need a lot of money."
Alot isn't a word. Never use it!
Allot means to give a portion of something.
"How much time should I allot to the speaker?"

Irregardless
Irregardless is NOT A WORD. Just drop the 'ir' and use regardless. Simple!