How to Write “The 30th” in English: A Simple Guide

Writing the 30th in English can seem tricky, but with a few simple rules, you’ll master it in no time. Whether you’re drafting an event invitation, a historical timeline, or a personal diary entry, knowing how to use the ordinal “30th” correctly adds clarity and professionalism to your writing.

Understanding Ordinals in English

Ordinals indicate position or order—first, second, third, and so on. They’re usually formed by adding “-th,” “-st,” “-nd,” or “-rd” to a number. English follows a few exceptions: 1st, 2nd, 3rd, and 11th‑13th always end with “th,” regardless of the unit digit. This rule is why 11th, 12th, and 13th break the pattern.

Why “30th” Matters in Everyday Writing

Accurate ordinal usage matters in contexts ranging from:

• Event dates: July 30th, 2024
• Historical milestones: The 30th anniversary of the treaty
• Sports standings: The team finished 30th in the league

Using the wrong form—like “30st” or “30nd”—can confuse readers and undermine credibility.

Steps to Write The 30th

Follow these straightforward steps to ensure you use “30th” correctly every time.

1. Identify the Number

Confirm that the number is thirty (30). This step avoids misreading “3rd” as “30th.”

2. Apply the Standard Suffix

For 30, append the “th” suffix: 30th. The rule is simple: any number ending in 0, 4, 5, 6, 7, 8, 9, or 0, except 11‑13, takes “th.”

3. Capitalize When Needed

If the ordinal starts a sentence or is part of a title, capitalize the first letter: 30th versus 30th.

4. Use Numerals or Words Consistently

Decide whether to write the number as digits or words. In most formal contexts, digits are preferred: 30th versus “thirtieth.” However, in literary prose, writing the word can add stylistic flair.

5. Double‑Check the Context

Ensure the ordinal correctly reflects the meaning. For instance, “He finished 30th in the race” vs. “He was 30th on the list of winners.” Both are correct but convey different nuances.

Common Mistakes to Avoid

• Writing “30st” or “30nd” instead of “30th.”
• Using “thirtyst” or “thirtieth” when a numeral is clearer.
• Mixing ordinal and cardinal forms: 30th place versus 30 place.
• Forgetting the “th” after numbers like 20, 40, 50, etc., which also end in “th.”

Practice Examples

Try rewriting these sentences to include the correct ordinal:

• My birthday is on July 30th.
• She finished 30th in the marathon.
• We celebrated the 30th anniversary of the company.
• The 30th chapter of the book is the most thrilling.

Notice how “30th” seamlessly fits into each context.

Quick Reference Table

Below is a handy table that shows common numbers and their ordinal endings:

• 1st, 21st, 31st, 41st, …
• 2nd, 22nd, 32nd, 42nd, …
• 3rd, 23rd, 33rd, 43rd, …
• 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, 13th, 14th, … 30th, 40th, 50th, …

Keep this list handy when drafting dates or rankings.

FAQs

What is the difference between “thirtyth” and “30th”?

“Thirtyth” is not a standard English form; the correct ordinal of the word thirty is “thirtieth.” “30th” is the numeric form and is widely accepted in formal writing.

When should I use the word “thirtieth” instead of the number?

In literary or poetic contexts, spelling out “thirtieth” adds rhythm and emphasis. In everyday prose, especially with dates, use the digit form for brevity.

Do I need to write “the” before “30th” in dates?

Yes. Standard date format includes “the”: the 30th of June or simply “30th June” in informal writing.

Is “30th” acceptable in titles and headings?

Yes, but capitalize the “3” if the ordinal begins a title: 30th Anniversary Celebration.

Mastering the use of “30th” is a quick win for clear, accurate writing. Keep this guide handy whenever you need to reference the 30th—whether it’s a calendar date, a ranking, or an anniversary—and you’ll always present a polished, professional tone.