Here are five of the common errors in English that come to mind. You can hear them often from native speakers and I am guilty of a few, too!!!

FEWER vs LESS

Wrong: "Checkout for 10 items or less"

Right: "Checkout for ten items or fewer"

If a noun is countable, you use "fewer"; if not, use "less". "To lose weight, you should consume fewer calories and less fat".

WENT vs GONE

Wrong: "You should have went to the concert"

Right: "You should have gone to the concert"

Of course, should + have needs a past participle!

TAKE vs BRING

Wrong: "When we go to the hospital, let's bring some oranges"

Right: "When we go to the hospital, let's take some oranges".

The verb "to go" starts from a point of departure, whereas the verb such as "to come" is at the arrival point. When you go, you take; when you arrive, you bring. So it would also be correct to say "When you come to the hospital, please bring some oranges".

WHO vs THAT

Wrong: "She is the girl that forgets her lines"

Right: "She is the girl who forgets her lines"

If it's a person, use who.

WHICH vs THAT

A pronoun "that" is a restrictive pronoun and "which" should be used to add information. The "which" part can be left out without changing the meaning of the main part of the sentence. The removal of "that" part would change the meaning of the sentence and that's why it's called restrictive.

"Sushi that is improperly prepared can give you parasites"

"Sushi, which is basically raw fish, is a Japanese delicacy"

If you remove the "which" addition, you are left with "Sushi is a Japanese delicacy" which is correct and does not change the meaning of the sentence. But if you remove the "that" section, it reads "Sushi can give you parasites" which is generally true but it completely changes the meaning and in some cases could even make the sentence not true.