são vs sei, What's the Difference?

Which to use

“são” is an adjective and “sei” is a verb - they look or sound alike but fill different roles in a sentence.

#20,080
“são” frequency rank: #185
“sei” frequency rank: 20265
confusion score

Side-by-Side Comparison

Feature	são	sei
Definition	gesund	2. Person Singular Präsens Imperativ Aktiv des Verbs sein

Where the spellings diverge

Shared letters are muted; the letters that actually set são and sei apart are highlighted. They share 1 letter in sequence, which is exactly why the eye skips the difference.

3 ch

são

3 ch

sei

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: são is [sɐ̃w] while sei is [zaɪ̯]. 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 (adjective vs verb), which is usually the fastest check. Our composite confusion score for this pair is 20265, derived from the frequency rank of both members and their visual similarity.

são is recorded at frequency rank #20,080, classified as anadj, pronounced [sɐ̃w]. sei is at rank #185, tagged as averb, pronounced [zaɪ̯].

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 20265, this pair ranks #1,899,560 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of são vs sei

Shared letters: s. Private to "são": oã. Private to "sei": ei.

"são" · 3 letters · shape CVV · "sei" · 3 letters · shape CVV

Frequency comparison

são#20,080

sei#185

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "são" and "sei" be used interchangeably?

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

Which is more common, "são" or "sei"?

"sei" is the more common of the two: it sits at frequency rank #185 in our German list, against #20,080 for "são". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Remembering são vs sei

The fastest way to pick the right one every time.

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