tau vs that, What's the Difference?

Which to use

“tau” is a noun and “that” is a pronoun - they look or sound alike but fill different roles in a sentence.

#33,347
“tau” frequency rank: #5,784
“that” frequency rank: 39131
confusion score

Side-by-Side Comparison

Feature	tau	that
Definition	La letra número 19 del alfabeto griego.	Ese, esa, esos, esas.

Where the spellings diverge

Shared letters are muted; the letters that actually set tau and that apart are highlighted. They share 2 letters in sequence, which is exactly why the eye skips the difference.

3 ch

tau

4 ch

that

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: tau is [ˈt̪aw] while that is /ðæt/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (noun vs pronoun), which is usually the fastest check. Our composite confusion score for this pair is 39131, derived from the frequency rank of both members and their visual similarity.

tau is recorded at frequency rank #33,347, classified as anoun, pronounced [ˈt̪aw]. that is at rank #5,784, tagged as apron, pronounced /ðæt/.

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 39131, this pair ranks #166,230 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of tau vs that

Shared letters: at. Private to "tau": u. Private to "that": h.

"tau" · 3 letters · shape CVV · "that" · 4 letters · shape CCVC

Known mistypes of this pair

that ← htat · taht · thatt · thhat · thta · tthat

Frequency comparison

tau#33,347

that#5,784

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "tau" and "that" be used interchangeably?

No - they are not even the same part of speech. "tau" is a noun and "that" a pronoun, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "tau" or "that"?

"that" is the more common of the two: it sits at frequency rank #5,784 in our Spanish list, against #33,347 for "tau". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Remembering tau vs that

The fastest way to pick the right one every time.

Check the role first: if you need a noun, it's “tau”; for a pronoun, it's “that”.
See each word in full, definition, IPA, etymology and its other confusables. Full “tau” entry
Browse more pairs most likely to be confused. Most confusable