daí vs def, What's the Difference?

Which to use

“daí” is a contraction and “def” is an adjective - they look or sound alike but fill different roles in a sentence.

#1,387
“daí” frequency rank: #32,132
“def” frequency rank: 33519
confusion score

Side-by-Side Comparison

Feature	daí	def
Definition	contração da preposição de com o advérbio de lugar aí:	algo muito bom

Where the eye mixes daí and def

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch

daí

3 ch

def

Look-alike desk: daí vs def

These two trip readers on the page rather than in the ear: daí is /dɐ.ˈi/ while def is /dɛf/. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (contraction vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 33519, derived from the frequency rank of both members and their visual similarity.

daí is recorded at frequency rank #1,387, classified as acontraction, pronounced /dɐ.ˈi/. def is at rank #32,132, tagged as anadj, pronounced /dɛf/.

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 33519, this pair ranks #33,981 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of daí vs def

Shared letters: d. Private to "daí": aí. Private to "def": ef.

"daí" · 3 letters · shape CVV · "def" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "daí" for "def" ever safe?

No - they are not even the same part of speech. "daí" is a contraction and "def" an adjective, so a sentence built for one is usually ungrammatical with the other.

Frequency check: "daí" vs "def" - which ranks higher?

"daí" is the more common of the two: it sits at frequency rank #1,387 in our Portuguese list, against #32,132 for "def". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

Full dictionary entry for "daí" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "def" - compare definitions side by side with the headword page. Word entry
This pair ranks #33,981 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"daí" and "def" also get mixed up with nearby pairs, the highest-scored neighbour is "dat vs def". Nearby pair

Confusion rank #33,981 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.