I'llvsillsWhat's the difference?

Quick tell: I'll is a contraction, ills is a noun, so they fill different roles in a sentence.

Which to use

“I'll” is a contraction and “ills” is a noun - they look or sound alike but fill different roles in a sentence.

#356
“I'll” frequency rank
#28,587
“ills” frequency rank
28943
confusion score

Side-by-Side Comparison

Feature I'll ills
Definition I will. plural of ill

Where the spellings diverge

Shared letters are muted; the letters that actually set I'll and ills apart are highlighted. They share 3 letters in sequence, which is exactly why the eye skips the difference.

4 ch
I'll
4 ch
ills

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: I'll is /aɪ̯l/ while ills is /ɪlz/. 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 noun), which is usually the fastest check. Our composite confusion score for this pair is 28943, derived from the frequency rank of both members and their visual similarity.

I'll is recorded at frequency rank #356, classified as acontraction, pronounced /aɪ̯l/. ills is at rank #28,587, tagged as anoun, pronounced /ɪlz/.

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 28943, this pair ranks #367,038 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of I'll vs ills

Shared letters: il. Private to "I'll": -. Private to "ills": s.

"I'll" · 3 letters · shape VCC  ·  "ills" · 4 letters · shape VCCC

Known mistypes of this pair

  • illsillss · ilsl · lils

Frequency comparison

I'll#356
ills#28,587

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "I'll" and "ills" be used interchangeably?
No - they are not even the same part of speech. "I'll" is a contraction and "ills" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "I'll" or "ills"?
"I'll" is the more common of the two: it sits at frequency rank #356 in our English list, against #28,587 for "ills". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Remembering I'll vs ills

The fastest way to pick the right one every time.

  • Check the role first: if you need a contraction, it's “I'll”; for a noun, it's “ills”.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “I'll” entry
  • Browse more pairs most likely to be confused. Most confusable

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

Source: FrequencyWords open word-frequency list