Flat adverbs = unchanged from adjective form

Definition of flat adverbs:

adjectives that do not change form (add -ly) to be become adverbs.

Examples: early, late, hard, fast, long, high, low, deep, and near.

To determine whether these words are functionning as adjectives or adverbs, you must dertermine:

1. What the word is describing? Noun or verb?
2. What question the word is answering?

Example :

• Early as adjective: The early train arrives at 8:45am. Early describes the noun train and answers the question "Which one?".
• Early as adverb: The 8:45 train arrived early. Early describes the verb arrived and answers the question "when?".

Example :

• Hard as adjective: The teacher gave a hard test. Hard describes the noun test and answers the question "what kind?".
• Hard as adverb: He threw the ball hard. Hard describes the verb threw and answers the question "How?".

Example :

• Fast as adjective: He drives a fast car. Fast describes what kind of car.
• Fast as adverb: He drives fast. Fast describes how he drives.

Adverbs modify Verbs, adjectives and other Adverbs. Examples:

• He never ceases to amaze me. modifies the verb "ceases".
• She is a very interesting scientist. modifies the adjective "interesting".
• He is sometimes quite boring. modifies the adverb "quite".