Definition of Fast
Quick Meaning of Fast
Able to move or happen very quickly, not slowly.
Detailed Definition of Fast
Moving or capable of moving at high speed; quick in action or response.
How to Pronounce Fast
Stress pattern: O (1-syllable word).
Tip: Use the AH sound as in father: FAHST. The A is long, not short like in apple.
Watch out: Some learners pronounce it with short A like in cat (fæst) instead of the long AH sound (fɑːst).
Origin and Etymology of Fast
From Old English fest, meaning firmly fixed; semantic shift to speed occurred in Middle English.
How to Use Fast in a Sentence
Each example shows “fast” with a CEFR level so learners can pick examples that match their fluency.
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“That car is very fast on the highway.”
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“She runs fast in the morning race.”
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“The internet connection is fast enough for streaming.”
Synonyms and Antonyms of Fast
Common Synonyms for Fast
Smart Synonyms for Fast — When to Use Each
- quick
- emphasizes ability to act or respond in short
- rapid
- describes speed of movement or process flow
- swift
- more formal or literary term for fast movement
Antonyms of Fast
Common Collocations with Fast
These phrases pair with “fast” in everyday English:
- fast car
- fast food
- fast runner
- run fast
- fast enough
Common Mistakes When Using Fast
Even fluent speakers slip up with “fast”. Here’s how to avoid the most common errors:
- ✗ Wrong: He runs fastly in the competition.
- ✓ Correct: He runs fast in the competition.
- Why: Fast is both adjective and adverb; the adverb form is fast, not fastly (fastly is not a word).
- ✗ Wrong: The weather is very fast.
- ✓ Correct: The weather is changing fast.
- Why: Fast describes speed of movement or action, not static weather conditions; only use it with verbs of motion.
Words Confused With Fast
- Fast vs Quick: Both mean speedy, but quick is more common for sudden or immediate actions Compare →
Other Forms of Fast
Frequently Asked Questions About Fast
What is the meaning of "Fast"?
Able to move or happen very quickly, not slowly.
How do you pronounce "Fast"?
The IPA is /fɑːst/. Use the AH sound as in father: FAHST. The A is long, not short like in apple.
What part of speech is "Fast"?
"Fast" is an adjective at A1 level (Common European Framework).
What are synonyms for "Fast"?
Common synonyms include quick, speedy, rapid.
How do you use "Fast" in a sentence?
For example: "That car is very fast on the highway."