Choosing between to fast and too fast matters because one is usually ungrammatical while the other is a common adverbial phrase that affects meaning. In this introduction we explain the difference clearly, label the parts of speech (nouns, verbs, adjectives, adverbs, prepositions, conjunctions, pronouns), and check verb tense and subject–verb agreement in sample sentences so you can write accurately.
Too (adverb) intensifies and modifies adjectives and adverbs: she ran too fast means she ran at an excessive speed. To (preposition or infinitive marker) is different: we say to run (infinitive) or to the store (preposition + noun). A sentence like He drove to fast is incorrect because to does not function as an intensifier; the correct form is He drove too fast.
Throughout this article, you will see contextual examples, diagnose common mistakes, compare American and British tendencies, explore idiomatic uses, and give practical tips for writers and editors. I will place modifiers next to the words they modify, check verb forms for correct tense and agreement, and revise awkward phrasing so your prose remains precise and natural.
Contextual Examples
Simple Comparative Example
Example: He (pronoun) ran (verb, past simple) too fast (adverb phrase) and (conjunction) fell (verb, past simple).
Analysis: Subject–verb agreement is correct: he (singular) + ran (past). Too (adverb) modifies fast (adverb) to indicate excess. The coordinating conjunction and links two verb phrases. This sentence shows how too fast functions as an adverbial phrase modifying the verb ran; it answers how he ran.
Infinitive Confusion
Faulty: She decided to fast the competition.
Why it’s wrong: Here to appears before fast, but fast as an adjective means “quick” and as a verb means “to abstain from food.” If the writer intended “to abstain,” then to fast (infinitive verb phrase) is grammatical: She decided to fast. If the writer intended “at excessive speed,” they need too fast: She drove too fast to win the competition. Context determines meaning; parts of speech differ: to as an infinitive marker + fast as verb vs too adverb + fast adjective/adverb.
Modifier Placement
Example: The (article) car (noun) moved (verb, past simple) too fast (adverbial phrase) down (preposition) the (article) hill (noun).
Analysis: Too fast sits directly next to the verb moved, which it modifies. The prepositional phrase down the hill follows and gives location. This order is clear and avoids dangling modifiers.
Adjective vs Adverb
Example Adjective: A (article) fast (adjective) runner (noun) won (verb) the (article) race (noun).
Example Adverb: She (pronoun) ran (verb) fast (adverb).
Intensified: She ran too fast (adverbial phrase).
Analysis: Fast can be an adjective (modifies a noun) or an adverb (modifies a verb). Too is an adverb that modifies fast when fast functions adverbially. Check verbs: won (past) agrees with runner (singular); ran agrees with subject she.
Instructional Contrast
Incorrect: Try to fast when shortening your code.
Correct: Try too fast when shortening your code? No — the correct instructional phrasing depends on intention. If a user should not do something at excessive speed, we might say: Do not work too fast; check output carefully. If a user should abstain from food before a test, say: You should fast (verb) before the test, or You should fast for twelve hours.
Clarity: Choose the phrase that matches intended meaning — to fast (infinitive verb) vs too fast (adverbial intensity).
Common Mistakes
Mistake: Confusing To and Too
Faulty: He typed to fast and crashed the script.
Why it’s wrong: If the writer meant “excessively fast,” the correct phrase is too fast. To is a preposition or infinitive marker, not an intensifier.
Fix: He typed too fast and crashed the script.
Parts of speech: he (pronoun), typed (verb, past simple), too (adverb), fast (adverb), and (conjunction), crashed (verb), the (article), script (noun). Check subject–verb agreement: he typed — correct.
Mistake: Using To Fast When Meaning To Abstain Without Context
Faulty: He wants to fast.
Why it may confuse: To fast (infinitive) is correct if the meaning is “to abstain from food,” but many readers see to fast and misread it as an error for too fast. Add context.
Fix: He wants to fast for religious reasons.
Parts of speech: he (pronoun), wants (verb, present simple), to (infinitive marker), fast (verb), for (preposition) religious (adjective) reasons (noun). Subject–verb agreement: he wants — correct.
Mistake: Splitting Too and Fast
Faulty: He moved to fast.
Why it’s wrong: Grammar requires too fast together when intensifying speed. Separating them creates a preposition + adjective awkwardness.
Fix: He moved too fast.
Grammar note: Keep too and the word it modifies adjacent when possible; place modifiers next to what they modify.
Mistake: Overusing Too Without Degree Limit
Faulty: The car was too fast but we didn’t use it.
Why it’s weak: Too fast implies that speed prevented some outcome; follow with a clause that explains the consequence: The car was too fast to handle safely. Add the infinitive clause to show result.
Better: The car was too fast to handle on icy roads.
Analysis: too (adverb) modifies fast (adjective). The infinitive clause to handle on icy roads explains the consequence.
Mistake: Double Adverbs
Faulty: She ran too very fast.
Why it’s wrong: Too and very both intensify; stacking them is ungrammatical or redundant.
Fix: She ran too fast. Or: She ran very fast.
Grammar rule: Use one degree adverb (too, very, extremely) to modify an adjective or adverb.
American vs British English Differences
Core Rule Is Universal
Both American and British English follow the same syntactic rule: too is an adverb used to modify adjectives or adverbs (too fast, too slow), and to is a preposition or infinitive marker. There is no dialectal difference in whether one writes too fast or to fast when meaning “excessively quick.”
Example (American): He was driving too fast.
Example (British): He was driving too fast.
Subtle Usage Notes
British English may sometimes use slightly different collocations or idioms— for example, British users might say “He’s a bit too fast for that” with “a bit” as a hedge. American English might more often use direct intensifiers without hedging in casual speech. But these are matters of tone and register, not grammar.
Verb Meanings And Context
When fast is used as a verb (to abstain from eating), both dialects accept to fast for the infinitive. Example: She plans to fast during the holiday. The verb meaning is clear in context and not dialect-dependent.
Idiomatic Expressions
Too Fast For Someone/Something
Example: That joke was too fast for the audience.
Analysis: Too (adverb) modifies fast (adverb). The phrase here idiomatically means the audience could not keep up. Parts of speech: that (demonstrative pronoun) joke (noun) was (verb) too (adverb) fast (adverb phrase) for (preposition) the (article) audience (noun).
Usage note: Use too fast when describing timing or complexity that exceeds the listener’s ability to follow.
Too Fast, Too Furious (Idiomatic Play)
Example uses: Too fast, too furious is a playful or emphatic pairing in idiomatic English. It uses too to intensify both adjectives in parallel.
Grammar check: Too (adverb) fast (adjective/adverb), too (adverb) furious (adjective). Maintain parallel structure.
To Fast As A Verb (Religious Or Medical Contexts)
Example: Many religions instruct followers to fast during certain observances.
Analysis: To (infinitive marker) fast (verb) — here the meaning is “to refrain from eating.” Make sure context clarifies the meaning to avoid readers misreading it as a typo for too fast.
Fixed Collocations With Too
• Too fast to stop — describes excessive speed with an infinitive result clause.
• Too fast for his own good — idiomatic extension meaning speed causes harm.
• Too fast, too soon — idiomatic phrases used in commentary and critique.
Each collocation uses too as an intensifier and requires grammatical agreement in the main clause.
Practical Tips
Tip 1: Read For Meaning, Not Just Sound
When you see to fast or too fast, slow down and ask what the sentence aims to say: is it about speed (excess) or about abstaining? Use context to choose the correct parts of speech.
Tip 2: Use Tests To Decide Between To and Too
Quick test: Try replacing too with very. If the sentence still makes sense, too is correct as an intensifier. Example: He ran very fast (makes sense) ⇒ so too fast is correct. If you cannot do this test, consider whether the infinitive meaning (to + verb) fits.
Tip 3: Keep Modifiers Next To What They Modify
Place too directly next to fast when intensifying speed: She drove too fast on the freeway. This prevents awkward splits and dangling modifiers.
Tip 4: Avoid Redundancy With Degree Words
Don’t stack degree modifiers: not too very fast, but very fast or too fast. Choose the one that matches the intended degree.
Tip 5: Clarify Ambiguous Infinitive Uses
When fast is a verb, provide context to prevent misreading: She plans to fast for medical reasons. If you must use the infinitive in a sentence where misreading is likely, restructure: She plans to observe a fast for medical reasons.
Tip 6: Use Result Clauses To Show Consequence
When using too fast, add the result clause to explain the consequence: The car went too fast to stop. This clarifies why speed was a problem.
Tip 7: Maintain Verb Tense And Agreement
Check verbs around too fast phrases: He (singular) was driving (past continuous) too fast, not He were driving. Keep subject–verb agreement straightforward.
Tip 8: Teach This Rule With Minimal Examples
For learners, show two-line contrasts:
Incorrect: He ran to fast.
Correct: He ran too fast.
Incorrect: She plans too fast.
Correct (infinitive): She plans to fast.
Correct (intensity): She plans to run too fast? No — context required.
Tip 9: Use Punctuation To Improve Clarity
Add commas when the sentence has additional clauses: Running late, he drove too fast to stop safely. The introductory phrase clarifies subject and action.
Tip 10: Read Aloud For Naturalness
Reading the sentence aloud often signals whether the phrasing sounds right or not. If “to fast” sounds abrupt and doesn’t fit the sense, try “too fast” instead.
Conclusion
The distinction between to fast and too fast hinges on parts of speech and intended meaning. Use too fast (adverb + adverb/adjective) to indicate excess speed or intensity, and use to fast only when fast is a verb in an infinitive construction meaning “to abstain.” Place too next to fast, avoid stacking degree adverbs, and add result clauses to clarify consequences. Check verb tense and subject–verb agreement around these phrases and keep modifiers close to what they modify. These small grammar checks make writing clearer, prevent misreading, and improve the credibility of your prose.
FAQs
- Q: Which is correct: “to fast” or “too fast”?
A: Too fast is correct when you mean “excessively quick.” Use to fast only when fast is a verb meaning “to abstain from food,” and include context to avoid confusion. - Q: Can “fast” be both verb and adverb?
A: Yes. Fast is a verb meaning “to abstain” (She will fast), an adjective (a fast car), and an adverb (He runs fast). Parts of speech determine whether to use to (infinitive) or too (degree adverb). - Q: How do I fix “He moved to fast”?
A: Replace to with the adverb too: He moved too fast. Check subject–verb agreement and verb tense around the phrase. - Q: Is “to fast” ever correct without context?
A: It can be grammatically correct as an infinitive (to + verb), but it often needs context to show you mean abstaining from food: She plans to fast next week. - Q: Can I say “too fast to stop”?
A: Yes. Too fast to stop is a common structure: too (degree adverb) + fast (adverb/adjective) + result infinitive clause to stop. - Q: Are there regional differences for “too fast”?
A: No major regional difference; both American and British English use too fast the same way. Tone and hedging (a bit, rather) may vary by register. - Q: Why is “too very fast” wrong?
A: Too and very both function as degree modifiers; combining them is redundant or ungrammatical. Choose one: too fast or very fast. - Q: How can I teach this to students simply?
A: Use contrast drills: show to vs too in minimal pairs and ask learners to decide if the meaning is “speed” or “abstinence.” Reinforce with result clauses like too fast to stop.
