obvsoiWhat's the difference?

Quick tell: ob is a conjunction, oi is a phrase, so they fill different roles in a sentence.

Which to use

“ob” is a conjunction and “oi” is a phrase - they look or sound alike but fill different roles in a sentence.

#139
“ob” frequency rank
#26,990
“oi” frequency rank
27129
confusion score

Side-by-Side Comparison

Feature ob oi
Definition leitet indirekte Fragesätze sowie Ungewissheit, Zweifel oder dergleichen ausdrückende Nebensätze ein (in Form von Subjekt-, Objekt- und Attributsätzen) ein Grußwort mit unverbindlichem Charakter

Where the eye mixes ob and oi

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

2 ch
ob
2 ch
oi

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: ob is [ɔp] while oi is [oj]. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - b in “ob” becomes i in “oi”, and the parts of speech differ too (conjunction vs phrase), which is usually the fastest check. Our composite confusion score for this pair is 27129, derived from the frequency rank of both members and their visual similarity.

ob is recorded at frequency rank #139, classified as aconj, pronounced [ɔp]. oi is at rank #26,990, tagged as aphrase, pronounced [oj].

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 27129, this pair ranks #1,806,884 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ob vs oi

Shared letters: o. Private to "ob": b. Private to "oi": i.

"ob" · 2 letters · shape VC  ·  "oi" · 2 letters · shape VV

Frequently Asked Questions

Can "ob" and "oi" be used interchangeably?
No - they are not even the same part of speech. "ob" is a conjunction and "oi" a phrase, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "ob" or "oi"?
"ob" is the more common of the two: it sits at frequency rank #139 in our German list, against #26,990 for "oi". 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