I would tend to write double-l, but Google gives me more single-l, so I'm guessing it's an Atlantic divide thing.

And I guess all the other *full words.

  • 11
    There seems to be a trend of "Is X/Y a British English/American English difference?" questions where X is a word, and Y is a typo.
    – Seamus
    Commented Nov 2, 2010 at 12:54
  • (I removed the "single-word-request" tag, because it doesn't seem to apply.)
    – Marthaª
    Commented Nov 2, 2010 at 14:55
  • 7
    @Seamus: This question reverses the trend, in this case X is a typo
    – Vinko Vrsalovic
    Commented Nov 2, 2010 at 20:05

2 Answers 2


I would say successfull is a typo. Neither Merriam-Webster nor Wiktionary mention it as an alternative spelling. The British National Corpus has 10695 cites for successful and exactly one for successfull. According to OneLook, 33 dictionaries have an entry for successful, but only Wordnik has a few cites for successfull (without a definition).

Edit: by popular request, I will add that the adverb successfully is written with two L's. Successfuly would be incorrect.

  • 4
    Yes, "successfully" is correct, but "successfull" is not. And OneLook seems to be a very nice resource for us here (+1 for that link too)
    – b.roth
    Commented Nov 2, 2010 at 9:24

Only full is spelled with two Ls. All other -ful words are spelled with only one L: helpful, successful, skillful, beautiful.

  • 4
    To add an especially interesting case: chock full vs chock-full vs chockful.
    – RegDwigнt
    Commented Nov 2, 2010 at 15:10
  • 3
    However, skillful vs skilful is a difference between en-us and en-gb. And full undoubles the l when used as a prefix too, as in e.g. fulsome and fulfil. Commented Sep 10, 2012 at 15:05
  • 3
    Interesting. If you fill a sock with pennies, do you have a sockful or a sockfull? Commented Mar 3, 2013 at 20:58

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