thatvsThuWhat's the difference?

Quick tell: that is a conjunction, Thu is a name, so they fill different roles in a sentence.

Which to use

“that” is a conjunction and “Thu” is a name - they look or sound alike but fill different roles in a sentence.

#10
“that” frequency rank
#24,339
“Thu” frequency rank
24349
confusion score

Side-by-Side Comparison

Feature that Thu
Definition Introducing a clause that is the object of a verb, especially a reporting verb or verb expressing belief, knowledge, perception, etc. A surname.

Letter map: that vs Thu

Shared letters muted; letters that set that and Thu apart highlighted. Shared run: 2.

4 ch
that
3 ch
Thu

Grammar separator: that vs Thu

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: that is aconjunction and Thuaname. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 24349, derived from the frequency rank of both members and their visual similarity.

that is recorded at frequency rank #10, classified as aconj, pronounced /ðət/. Thu is at rank #24,339, tagged as aname.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 24349, this pair ranks #402,610 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of that vs Thu

Shared letters: ht. Private to "that": a. Private to "Thu": u.

"that" · 4 letters · shape CCVC  ·  "Thu" · 3 letters · shape CCV

Known mistypes of this pair

  • thathtat · taht · thatt · thhat · thta · tthat

Frequently Asked Questions

Can "that" and "Thu" be used interchangeably?
No - they are not even the same part of speech. "that" is a conjunction and "Thu" a name, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "that" or "Thu" show up more?
"that" is the more common of the two: it sits at frequency rank #10 in our English list, against #24,339 for "Thu". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Done with this confusable. These links stay specific to "that" and "Thu".

  • Full dictionary entry for "that" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "Thu" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #402,610 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "that" and "Thu" also get mixed up with nearby pairs, the highest-scored neighbour is "Taf vs Thu". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #402,610 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list