I was writing an email in Outlook and its grammar correction suggested I change this:

I need to do something, then I'll call you.

to this:

I need to do something, and then I'll call you.

Is the "and" needed there to be correct?

  • This is a really common error. "Then" is not a conjunction, and as such, cannot be used to combine two independent clauses.
    – Roger
    Jun 26, 2014 at 17:27
  • 1
    @Roger Yes. Iris Murdoch, Samuel Beckett, E. M. Forster, and Somerset Maugham didn't seem to know your rule. Or think it was as much a rule as you imply. Apr 4, 2015 at 21:35
  • 1
    @EdwinAshworth Yes, surprisingly, there are plenty of authors who have used grammar incorrectly in their works. Joyce loved the sentence fragment. Hemmingway used the run-on to great effect. Doesn't make it any less of an error in formal writing. Saying "<Famous Author> did X, so X must not be wrong" is called "argument from authority" and is a logical fallacy. The only true conjunctions from a grammatical standpoint are: for, and, nor, but, or, yet, and so -- easily remembered using the mnemonic FANBOYS.
    – Roger
    Apr 5, 2015 at 22:12
  • Is this Roger's grammar? The FANBOYS myth has been exploded on ELU before. And a far greater concern than citing recognised writers using grammar in ways some don't consider proper is stating 'rules' without any authority whatsoever. Wikipedia has a balanced view on the acceptability of sentence fragments; Truss is quoted as saying that their acceptability seems to be in proportion to the fame of the user. 'I came, I saw, I conquered' seems accepted. Apr 5, 2015 at 23:23
  • ... Dictionary.com licenses this usage of when: next in order of time: We ate, then we started home. I assume they've done their corpus analysis to allow this usage as being idiomatic, though I agree their word-classing is wrong here. AHDEL (see answer below) suggests that those not allowing the coordinator usage of then are in a minority (and gives them an unattractive name). Apr 5, 2015 at 23:50

5 Answers 5


This is from Cambridge.org. They're relatively authoritative.

Then meaning next: we can use then to mean next:

For Example:

He opened the door, then the lights came on and everybody shouted, ‘Happy Birthday’.

Heat some olive oil in a pan, then add some chopped garlic and some salt.


I'd recommend that the non-prescriptivist view given in AHDEL be accepted as most sensible here:

Usage Note: Sticklers for grammar sometimes assert that then is not a coordinating conjunction, and that the sentence [period omitted here]

She took a slice of pie, then left

is thus incorrect; it must be rewritten as

She took a slice of pie and then left

in which the then acts as an adverb and the halves of the compound predicate are linked by the coordinating conjunction and.

But this use of then as a coordinating conjunction is actually both widespread and widely accepted; in our 2012 survey, more than three quarters of the Usage Panel found the sentence She took a slice of pie, then left completely acceptable. Note, though, that the punctuation of this conjunctive use of then differs from the usual punctuation for similar sentences using and. No comma is needed when and links the parts of a compound predicate, as in She took a slice of pie and left. When then joins the halves of the predicate, a comma is usually required; only 8 percent of the Panel approved of She took a slice of pie then left.

Though the repeated subject is deleted in this example, the accepted role of then as a coordinator is spelled out. She took a slice of pie, then she left is not too far from the example sentence.

  • I was with you until you drew the conclusion that She took a slice, then she left. It just doesn't sound right to me. Jul 28, 2019 at 20:13
  • In their 2012 survey, more than three quarters of the AHD Usage Panel found the sentence 'She took a slice of pie, then left' completely acceptable. Sadly (for us), 'She took a slice of pie, then she left' wasn't a sentence the panel were asked to evaluate. However (a) it is the 'precursor' (before conjunction deletion, an accepted practice) of the '75% acceptable {in 2012, at AHD}' 'She took a slice of pie, then she left' which (b) is obviously comparable to OP's 'I need to do something, then I'll call you'. Jul 29, 2019 at 10:26

You are attempting to join two independent clauses with a comma. This is called a comma-splice error.

Here are your customary choices:

  1. I need to do something; then I’ll call you.
  2. I need to do something. Then I’ll call you.
  3. I need to do something, but then I’ll call you.
  4. I need to do something, and then I’ll call you.
  5. I need to do something and then I’ll call you.
  6. Disable Microsoft.

I of course suggest the lattermost option. :)

  • 2
    +1 (but I'm only upvoting option #6, natch! :) Jun 26, 2014 at 17:17
  • Your answer also led me to this discussion
    – TecBrat
    Jun 26, 2014 at 18:20
  • It's actually just 'comma splice', error is redundant. (Couldn't resist.)
    – Merk
    Jun 27, 2014 at 3:31
  • 1
    Just disable the "check grammar as you type" feature. Then, when you elect to grammar-check your doc (F7): the first time it finds that usage and complains, select Ignore This Rule. Apr 6, 2015 at 2:17
  • 5a. I need to do something--then I'll call you. At least it's not a comma splice.
    – Xanne
    Oct 22, 2017 at 8:03

I am a teacher of English and have experienced this kind of use confusing. At first, my learners kept using it in speech and I always advised them to avoid using and+then as it sounded incorrect in my ears.

Later on, I realised they also used it in every kind of writing assigned to them. In a form of reaction, I chose to have a quick review about types of sentences with their syntax and semantics. I hoped that it was going to add a particular value to their understanding. Surprisingly, they have not changed to using one at a time. I am afraid I misled them, but still believe the two can't go together except when 'then' refers to time. Example: I will be visiting you every now and then.

  • Actually "and then" is fine. At issue is the use of then as a coordinating conjunction. In many cases where it is so used, especially in formal contexts, a dash or a semi-colon might be used. "The sky darkened; then the storm came." But see Edwin Ashworth's answer.
    – Xanne
    Oct 22, 2017 at 7:53

I have taught college-level writing for ten years, and I have recently received an inordinate number of essays with this error of usage. It is a connector of two independent clauses, and the writer should be aware of the usage. THEN is a conjunctive adverb and should stand alone, punctuated with a comma, as a connector. I recently experienced the MS Office 10 programming error when I created an assignment sheet for an essay. Its programming determined my usage in error and replaced the correct usage with "and then" -- turn the auto correct off.

  • 4
    Why should "and then" be considered an "error of usage"?
    – herisson
    May 20, 2017 at 19:08
  • Aware they should be. It seems to be a register issue.
    – Xanne
    Oct 22, 2017 at 7:59

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