In some cases, the adverb may have two forms, one like the adjective and the other with -ly. There is usually a difference of meaning or use. Some examples are given below.
Dead and Deadly
In certain expressions, the adverb dead is used to mean exactly, completely or very.
Examples are: dead certain, dead slow, dead right, dead drunk etc.
Deadly is an adjective. It means fatal, causing death. The adverb for this meaning is fatally.
- Cyanide is a deadly poison.
- She was fatally injured.
Fine and Finely
The adverb fine means well.
- ‘How are you?’ ‘I am fine.’
The adverb finely is used to talk about small careful adjustments and similar ideas.
a finely tuned machine
Free and Freely
When used after a verb, the adverb free means without payment.
- Buy two shirts and get one free.
- Can I eat free in your restaurant?
Freely means without limit or restriction.
- Speak freely.
Hard and Hardly
The adverb hard means heavily, severely or with difficulty.
- You must work hard.
Hardly means almost not.
- I have hardly any money left.
Late and Lately
The adverb late has a similar meaning to the adjective late. Lately means a short time ago and recently.
- We will be late for dinner.
- It is getting late.
- I have not read anything lately.
Most and Mostly
Most is the superlative of much. It is used to form superlative adjectives and adverbs.
- Those who have the most money are not always the happiest.
- What pleased me most was his helping nature.
In a formal style, most can mean very.
This is a most (=very) interesting book.
Mostly means chiefly, generally or in most cases.
- My friends are mostly non-smokers.
Real and Really
In informal American English, real is often used before adjectives and adverbs. It means the same as really.
- That was real nice. (=really nice)
- She sings real well. (=really well)
Sure and Surely
In an informal style, sure is often used to mean certainly. This is common in American English.
- ‘Can I borrow your bicycle?’ ‘Sure.’