Used and loved by millions
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com
the 4th one
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "the 4th one" is correct and usable in written English.
You can use it to reference a particular item out of multiple items which are being discussed. For example, "Of the five options discussed, I believe the 4th one is the most viable."
✓ Grammatically correct
Science
News & Media
Wiki
Alternative expressions(20)
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Human-verified examples from authoritative sources
Exact Expressions
5 human-written examples
rebels in Aleppo murder yet another opposition activist, Abdullah Yassin – this is the 4th one now https://t.co/H7LriFF1BE #Syria — edward dark (@edwardedark) 3 Mar 13 I am officially, as of now neutral in #Syria 's ongoing civil war.
News & Media
The 4th one is a situation that the EU does not encounter yet (though the EU contains countries of different sizes, but its core countries are similar in size); it is easy to rise up and become a big obstacle.
For example, suppose we have two priority queues, and the 1st, 2nd, 3rd most optimal nodes are in the first priority queue while the 4th one is in the second queue.
Science
From the same middle peg (the 4th one) place a band diagonally to the left, and again to the right.
Wiki
the third one is to be able to tap the signal out to an inverse checker, basically, a site check to ping if it's up or not, and the 4th one is a stabilizer.
Wiki
Human-verified similar examples from authoritative sources
Similar Expressions
55 human-written examples
AUDIENCE: The 95 one's a hurdle.
This is the 10th one, the 10th Fibonacci number.
"I will win the 500 one day".
News & Media
Won one in the 70s, one in the 80s, and one the 90s.
News & Media
The third and most gala opening was the 9 30 one.
News & Media
But the CO2/NH3 cycle was the inherently safer cascade system in comparison with the CO2/C3H8 one.
Science
Expert writing Tips
Best practice
When using "the 4th one", ensure the context clearly establishes what the "one" refers to, avoiding ambiguity for the reader. For example, "We reviewed three proposals; the 4th one arrived late."
Common error
Avoid using "the 4th one" if it's not immediately clear what the "one" represents. Rephrase to specify: "the 4th option" or "the 4th point" for clarity.
Source & Trust
83%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "the 4th one" functions as a determiner phrase identifying a specific item within a sequence. It is used to point out a particular element based on its ordinal position in a series, as demonstrated by Ludwig's examples.
Frequent in
News & Media
25%
Science
50%
Wiki
25%
Less common in
Formal & Business
0%
Encyclopedias
0%
Social Media
0%
Ludwig's WRAP-UP
In summary, "the 4th one" is a grammatically sound and usable phrase for designating a specific item in a sequence. Ludwig AI affirms its correctness for written English. Although its usage is relatively rare, primarily appearing in scientific publications, news, and wikis, it effectively serves the purpose of specification and differentiation. For contexts demanding heightened formality, consider substituting it with alternatives like "the fourth item" or "number four". Always ensure the context provides a clear antecedent for what "the 4th one" refers to.
More alternative expressions(10)
Phrases that express similar concepts, ordered by semantic similarity:
the fourth item
Replaces "one" with the more formal word "item".
the fourth option
Substitutes "one" with "option", implying a choice among alternatives.
the fourth element
Replaces "one" with "element", often used in technical or structured contexts.
number four
Uses a more direct numerical reference instead of an ordinal phrase.
the fourth in line
Specifies a sequential order in a line or queue.
the fourth instance
Replaces "one" with "instance", suitable for referring to occurrences.
the fourth example
Substitutes "one" with "example", suitable for giving an example from the list.
the fourth candidate
Replaces "one" with "candidate", suitable for scenarios of a choice in selection process.
the fourth alternative
Substitutes "one" with "alternative", appropriate when presenting choices.
the fourth consideration
Replaces "one" with "consideration", often used in decision-making processes.
FAQs
How to use "the 4th one" in a sentence?
Use "the 4th one" to refer to a specific item in a numbered or ordered list. For example: "We evaluated several options and found "the 4th one" to be the most promising."
What can I say instead of "the 4th one"?
You can use alternatives like "the fourth item", "the fourth option", or "number four" depending on the context.
Which is correct, "the 4th one" or "the fourth one"?
Both are grammatically correct and mean the same thing. "The 4th one" is slightly less formal and more common in speech, while "the fourth one" is more formal and often seen in writing.
Is it okay to use "the 4th one" in formal writing?
While grammatically correct, "the 4th one" may sound slightly informal for very formal contexts. Consider using a more precise term like "the fourth alternative" or "the fourth point" for greater clarity and formality.
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Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
83%
Authority and reliability
4.5/5
Expert rating
Real-world application tested