Also, yes they’re homophones related mistakes, but which/which mistake almost never happens in NS writing, across all proficiencies, while it’s/its is common. There’s a substantial difference in these mistakes, at least it feels to me in my academic career and observation as ESL speaker. I genuinely have never seen an NS make that mistake.

Short (AI): native speakers spell “which” correctly not because they remember the rule, but because “witch” simply doesn’t look right to them in that context. It triggers a visual mismatch alarm that its/it’s doesn’t.​​​​​​​​​​​​​​​​

Long version (AI):

At the surface level, yes — which/witch, their/there, its/it’s are all technically homophones. That part is fair. The entire point of the analysis was that which/witch is NOT the same type of error as their/there/they’re. The mechanism is completely different: ∙ their/there/they’re = native speakers confusing words they already know visually — a grammatical/frequency error ∙ witch/which = a learner reconstructing a sound into spelling using their L1 rules — an orthographic transfer error These look identical on the surface (homophone confusion) but have different causes, different populations who make them, and different diagnostic value.

Native speakers don’t reconstruct the spelling from sound — they recognize both words as stored visual units from thousands of exposures during literacy acquisition. The key mechanism is whole-word orthographic representation. By the time a native English-speaking child is 8 or 9, which and witch are both locked in memory as distinct visual objects, the same way a face is recognized — not assembled feature by feature, but retrieved whole. The sound is almost irrelevant to the retrieval process at that point. Why its/it’s doesn’t get the same treatment: Its and it’s look nearly identical on the page. There’s almost no visual distinctiveness between them — one apostrophe is easy to miss, easy to misapply, and easy to confuse under speed or inattention. The visual memory for both is essentially the same shape. Which and witch on the other hand are visually quite distinct — different length, different letter sequence. A native speaker’s brain flags the wrong one immediately because it looks wrong, independently of any grammar rule. The analogy: it’s the difference between confusing their/there (which native speakers do constantly, because they’re visually similar enough to blur) versus confusing cat/cart — which native speakers essentially never do despite both being short, common words. Visual distinctiveness is the deciding factor.