sovssuWhat's the difference?

Quick tell: so is a conjunction, su is a noun, so they fill different roles in a sentence.

Which to use

“so” is a conjunction and “su” is a noun - they look or sound alike but fill different roles in a sentence.

#33
“so” frequency rank
#8,094
“su” frequency rank
8127
confusion score

Side-by-Side Comparison

Feature so su
Definition Reduced form of 'so that', used to express purpose; in order that. Alternative form of xu (“former Vietnamese currency”).

Letter map: so vs su

Shared letters muted; letters that set so and su apart highlighted. Shared run: 1.

2 ch
so
2 ch
su

Spelling & Dictionary Insight

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: so is aconjunction and suanoun. On the page they differ by a single letter - o in “so” becomes u in “su”. Our composite confusion score for this pair is 8127, derived from the frequency rank of both members and their visual similarity.

so is recorded at frequency rank #33, classified as aconj, pronounced /səʊ/. su is at rank #8,094, tagged as anoun.

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 8127, this pair ranks #504,001 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of so vs su

Shared letters: s. Private to "so": o. Private to "su": u.

"so" · 2 letters · shape CV  ·  "su" · 2 letters · shape CV

Frequently Asked Questions

Can "so" and "su" be used interchangeably?
No - they are not even the same part of speech. "so" is a conjunction and "su" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "so" or "su"?
"so" is the more common of the two: it sits at frequency rank #33 in our English list, against #8,094 for "su". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

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

Source: FrequencyWords open word-frequency list