Fourth and forth sound the same, but they do different jobs. One connects to the number four. The other expresses movement, progress, or something coming into view.
This difference matters in common phrases. A runner finishes fourth, a proposal is put forth, and people travel back and forth. The US holiday is the Fourth of July, not the Forth of July.
Because the words are homophones, you cannot hear the spelling difference in conversation. You must choose by meaning. This guide explains the grammar, tone, common expressions, and practical checks that make the choice easy.
Quick Answer
Use fourth when you mean number four in a sequence, a number-four position, or one of four equal parts. Use forth when you mean forward, onward, outward, or into view.
- Fourth: Maya finished fourth in the race.
- Forth: The committee put forth a new proposal.
The words are both correct, but they are not interchangeable.
Why People Confuse Them
The main problem is sound. In standard American English, fourth and forth are pronounced alike: “FORTH.” That makes them homophones—words with the same pronunciation but different spellings and meanings.
Their spelling is also close. Fourth has only one extra letter, u, and that letter sits inside four. Writers may miss it when typing quickly, especially in familiar expressions such as back and forth or Fourth of July.
The clearest memory aid is simple:
- Fourth contains four.
- Forth begins like forward.
Key Differences At A Glance
- Fourth
- Relates to the number four
- Marks order, rank, dates, or fractions
- Can function as an adjective, noun, or adverb
- Sounds neutral in everyday and formal writing
- Forth
- Means forward, onward, outward, or into view
- Usually functions as an adverb
- Often appears in established expressions
- Can sound formal or literary outside common phrases
Meaning and Usage Difference
Fourth identifies number-four position. It follows first, second, and third.
- This is our fourth meeting.
- He lives on the fourth floor.
- Elena came fourth in the final.
- One fourth of the class was absent.
In the first two examples, fourth modifies a noun. The third example uses it to indicate a finishing position, while the final one names one of four equal parts.
Forth points to movement or development. It can mean forward in place or time, outward from a place, or into notice.
- The hikers moved forth at sunrise.
- New leaves sprang forth after the rain.
- She put forth a practical solution.
- From that day forth, the rule remained in effect.
The pronunciation does not help you choose because both words sound alike. The sentence meaning decides the spelling.
Tone, Context, and Formality
Fourth is neutral. It fits casual speech, schoolwork, business writing, news, sports, dates, measurements, and formal documents.
Forth has mixed tone. It sounds completely natural in fixed expressions such as back and forth, put forth, set forth, and and so forth. However, standalone uses such as “venture forth” or “from this day forth” may sound formal, ceremonial, or literary.
That tone difference does not change the basic rule. Use fourth for number-four ideas and forth for forward or outward ideas.
Which One Should You Use?
Use the sentence’s purpose as your test.
| Context | Best Choice | Why |
| Position after third | fourth | It marks number-four order |
| A date involving day four | fourth | It refers to the fourth day |
| One of four equal parts | fourth | It names a fraction |
| Forward or onward movement | forth | It expresses direction or progress |
| Something presented for consideration | forth | It means brought into view |
| Repeated movement between sides | forth | The standard phrase is “back and forth” |
A fast check also works: If you can connect the idea to four, choose fourth. If forward, onward, or outward fits, choose forth.
When One Choice Sounds Wrong
A sentence sounds wrong when the spelling conflicts with the intended meaning.
- Incorrect: She was forth in line.
- Correct: She was fourth in line.
The sentence gives a numbered position, so it needs fourth.
- Incorrect: The team put fourth a new plan.
- Correct: The team put forth a new plan.
The plan is being presented, not numbered.
- Incorrect: We drove back and fourth all afternoon.
- Correct: We drove back and forth all afternoon.
The phrase describes movement in opposite directions.
- Incorrect: Happy Forth of July!
- Correct: Happy Fourth of July!
The holiday name refers to July’s fourth day.
Common Mistakes (and Quick Fixes)
Mistake: Writing “back and fourth.”
Fix: Use back and forth. Think of movement going forward and then back.
Mistake: Writing “Forth of July.”
Fix: Use Fourth of July because the holiday falls on day four of July.
Mistake: Using forth for a numbered position.
Fix: Numbered positions connect to four: fourth place, fourth in line, and finished fourth.
Mistake: Using fourth in a formal phrase.
Fix: Write set forth the terms, put forth an idea, and from this day forth.
Mistake: Assuming one is a regional spelling.
Fix: They are separate English words, not American and British variants.
Everyday Examples
- Our fourth delivery arrived before noon.
- The speaker put forth three possible solutions.
- Jayden moved into fourth place during the last lap.
- Emails went back and forth until both teams agreed.
- Please read the fourth paragraph again.
- The policy sets forth the refund conditions.
- We used one fourth of the paint.
- The sun broke forth from behind the clouds.
- Her apartment is the fourth door on the right.
- From that week forth, meetings started on time.
Each sentence points either to four or to forward, outward, or presented movement.
Dictionary-Style Word Details
Verb
- Fourth: Not commonly used as a verb in standard US English.
- Forth: Not commonly used as a verb by itself. It usually works as an adverb with verbs such as go, bring, put, set, spring, or send.
Noun
- Fourth: A noun meaning the number-four member of a series, one of four equal parts, a musical interval, or an understood number-four position.
- Forth: Not commonly used as a common noun in this comparison. Its standard everyday role is adverbial.
Synonyms
- Fourth: Closest plain alternatives depend on meaning: 4th, number four, or one quarter. No single alternative covers every use.
- Forth: Common alternatives include forward, onward, and sometimes outward. Back or backward can act as contextual opposites, but no single opposite fits every phrase.
Example Sentences
- Fourth: The fourth applicant had the strongest portfolio.
- Fourth: Add one fourth of a cup of water.
- Forth: The witness came forth with new information.
- Forth: The manager set forth the expectations in writing.
Word History
- Fourth: Developed from four with an ordinal ending that marks order.
- Forth: Comes from an older English word connected with forward or onward movement.
The similar modern spelling does not mean the two words are variants of one another.
Phrases Containing
- Fourth: fourth place, fourth quarter, fourth floor, one fourth, Fourth of July
- Forth: back and forth, put forth, set forth, bring forth, go forth, and so forth, from this day forth
FAQs
Use fourth in a sequence because it means the position after third. Write “the fourth student,” “our fourth meeting,” or “she finished fourth.” Forth does not mark numerical order, so it would be incorrect in those sentences.
Write Fourth of July because the holiday name refers to the fourth day of July. In this name, Fourth is commonly capitalized. Forth of July is incorrect because forth expresses forward or outward movement, not a calendar date.
No, fourth and forth are not interchangeable. They sound alike, but they carry different meanings and grammatical roles. Use fourth for number-four order or one of four equal parts; use forth for onward, outward, or into view.
No, the standard expression is back and forth. It describes repeated movement, communication, or change between two sides or positions. Use back-and-forth with hyphens before a noun, as in “a back-and-forth discussion.”
Yes, fourth can stand alone when the missing noun is understood. You can say “I finished fourth,” “the fourth was damaged,” or “one fourth is missing.” The exact role changes with context, but the word still relates to four.
Sometimes. Forth can sound formal or literary in expressions such as “go forth” or “from this day forth.” However, it remains completely natural in established phrases such as “back and forth,” “put forth,” “set forth,” and “and so forth.”
Conclusion
Choose fourth for anything tied to the number four: order, rank, dates, or fractions. Choose forth for movement or development that goes forward, outward, or into view.
The easiest reminder is built into the spelling: fourth contains four, while forth points forward. That check solves common errors such as back and fourth, Forth of July, and put fourth an idea.
