The past tense of to occur is occurred (not occured), but the past tense of to listen is listened (not listenned).

Why? What is the general rule that is applied to make the past tense of a verb?

  • 2
    Just a side note: this is not limited to verbs. Note that the consonant is doubled in bigger, hipper, thinner, but not in neater, weirder, broader.
    – RegDwigнt
    Aug 30, 2010 at 2:38
  • 5
    English spelling is so inconsistent that any answer is going to be pretty useless, because you can't really predict anything reliably. I think the best answer is that it has to do with vowel quality (particularly short v. long), but doubling is often not applied. There is coming and homing and bombing and combing, living and diving, etc. (I am not saying the observation isn't interesting.)
    – Kosmonaut
    Aug 30, 2010 at 15:50
  • @Kosmonaut: In the specific case, there is a reason because you write occurred, barred, and listened. On English Grammar I found a "rule" described with words that are different from the ones used by Shinto Serlock; if I apply one or the other "rule", I obtain the same result. Come is an irregular verb; live is a regular verb, but it doesn't follow the schema CVC (or, following the rule I read, it's a single syllable word, and its last two letters are not a vowel and a consonant).
    – apaderno
    Aug 30, 2010 at 19:40
  • If there were two different verbs, listen and listene, then indeed the past of listen would probably be listenned to distinguish it from listened which would be the past of listene. But, since we have no verb listene, there is no reason to double this n.
    – GEdgar
    Apr 29, 2016 at 18:34

3 Answers 3


Occur has its stress on the final syllable (o-CUR) but listen (LIS-en) has its stress on the first syllable. If the verb ends in the pattern consonant-vowel-consonant, the final consonant is doubled in the case of verbs like refer and occur and begin where the stress is on the final syllable (referrer, referring, referred, occurrence, occurred, beginning), or one syllable words (big -> bigger, sin -> sinner) but not in the case of verbs like listen or broker (listened, listener, brokered, etc.), where the stress is non-final.

  • 4
    ... except in barred, stirred, spurred...
    – Timwi
    Aug 28, 2010 at 14:37
  • 4
    It’s a shame you edited this out of your answer because I think it is an interesting question. Why do barred etc. double the r, but cleared, poured and roared don’t? My guess is that it probably has something to do with vowel length in Middle English, or these words used to be bisyllabic (as indicated by the use of two vowel letters), but I would only be speculating.
    – Timwi
    Aug 28, 2010 at 14:44
  • 1
    Bar, and clear contain a single syllable, while occur is a two syllables word. It seems there are two rules that are applied depending on the number of syllables.
    – apaderno
    Aug 28, 2010 at 16:09
  • 1
    @Timwi: in German, the consonant letter is doubled if the preceding vowel sound is short, suggesting that your guess is not far off.
    – RegDwigнt
    Aug 28, 2010 at 16:16
  • 1
    @Timwi: I'd tend to agree that it probably has something to do with vowel length. Bar is from O.Fr. barre while bare is from O.E. bær, a long-short distinction, and though I can't say anything about the rare stire (a possibly extinct variety of apple) and nonexistent spure, all of clear, pour, and roar had long vowels in Middle English.
    – Jon Purdy
    Feb 7, 2011 at 20:24

I guess it's to retain pronunciation. If you don't double the ending consonant, it will be ok-cured (occured) instead of occur-ed (occurred), buy-ger (biger) instead of big-er (bigger), bay-red (bared) instead of bar-ed (barred), etc.

Seems intuitive and natural to me, though I can't confirm. If I'm right, the general rule would be not to double unless pronunciation changes.


I think it is due to the consonant letter (r) which comes at the end of the word occur. Based on what I studied, if the word ends with a consonant letter and before it comes a vowel letter, we should double the end letter in the past tense such as occurred, whereas in the word listen we shoudn't double the last letter because this is an irregular case. If the word has a primary stress on the left part, we should double the last letter: for example occur the primary stress occurs in the left part of the word (oc'cur) whereas in the word listen the premary stress occurs in the right part of the word (listen') so we shoudn't double the last letter.

  • Hello. I have corrected a few spelling mistakes in your post; I hope you don't mind. There are still some problems with what you say. I think you've switched around the position of the stress: in "occur," the stress occurs on the right syllable (cur) and in "listen," the stress occurs on the left syllable (lis).
    – herisson
    Apr 29, 2016 at 20:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.