Rather than trying to describe my beef with this idiom, I will give a bunch of successively objectionable examples. None of these are taken from real life.

As I see it, if (and when) both "if" and "when" are used, they should both describe the following statement.

(in an argument) If and when you admit defeat, I will be gracious.

This example is a perfect instance of this: "you" have not admitted defeat and it is not certain that you will, but "I" am promising to receive it with grace when it does happen. "I" am not offering to make an exchange (which is what "if you admit defeat, I will be gracious") would imply), nor am "I" expressing bravado (which is what "when you admit defeat, I will be gracious" would imply). The combination of circumstance and syntax produces a perfectly neutral conditional.

(planning a war) If and when this country is invaded, we must be ready to fight.

This is more or less equally good at expressing unbiased uncertainty, though I suspect the speaker really meant to say "We must be prepared for an invasion", and thus, "We must be prepared! (Because we are at war and might get invaded)".

(concerning a pregnancy) If and when we have a boy, we must name him after my father.

This has some false confidence leaking through, since with a pregnancy underway, whether or not the child is a boy is not in question (even if it is unknown).

(family planning in general) If and when we have a boy, we must name him after my father.

This is actually expressing an agenda, and has very little to do with conditional action. The speaker intends to continue trying for a boy until one is born. Indeed, no pregnancy is yet extant, so the pure "if" statement is at best wishful thinking, while the pure "when" statement is expressing false certainty about an event over which one has no control.

(preaching caution) If and when this country is invaded, we must be ready to fight.

This is worse than the 2nd example because the speaker is actually raising from nowhere the possibility of an invasion, and simultaneously elevating it to certainty. You, the reader, may have the intended reaction to the statement "If and when the dollar becomes worthless", which can probably actually be heard these days.

(estate planning) If and when I die, I want you to have everything.

This is silly: everyone dies. There is no "if" about it. On the other hand, in circumstances where untimely death is a possibility, it would be inappropriate to say "when".

(sarcasm) If and when I ever learn the meaning of life, I will let you know.

This is even sillier: there is no possibility of "when". Without the possibility of "when", the "if" also means something else: it is no longer a true conditional or even a counterfactual; such a statement can only be sarcastic.

Here's my question, then: what connotation is this idiom "supposed" to have? What, at least, does it usually have? Does the "if" or the "when" dominate or are they intended to be balanced, as I think? And finally, as the title suggests, what difference does it make if their order is reversed?

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    I doubt many people have ever said If and when I die, and if they did, they already weren't in their right mind, so you wouldn't want to hear it from grandpa dictating his last will and testament. Might give the disinherited relatives scope for contesting the will on the grounds he didn't know what he was saying! :-) Commented Jun 21, 2011 at 1:53
  • Argh! I hate if/when. They are contradictory, unlike the and/or combination, when used correctly. I am certain somebody made it up, in attempt to sound intelligent. Commented Jun 21, 2011 at 4:12
  • I live in Sweden and work as a translator. A translation agency just asked me for an offer. Their reply (in Swedish) to my offer was, "Thank you, we'll let you know if and when the end-customer accepts your offer." My interpretation is that they meant, "We'll get back to you when we find out whether or not the customer has accepted your offer." I wonder whether that is not a frequent usage of "if and when" in English also.
    – user86713
    Commented Jul 30, 2014 at 12:07
  • I think "when" is this context means "at the moment when" (Given that this country will be invaded, we must be ready to fight. Furthermore, we must be ready to fight at the moment of invasion) rather than asserting the assumption (If he dies tomorrow, I will cry. --> When he dies tomorrow, I will cry)? yugioh.wikia.com/wiki/Missing_the_timing
    – BCLC
    Commented Jun 11, 2015 at 15:54
  • Related: Difference between "when" and "if" in a sentence. I think that it is misleading to characterise if and when as an idiom. If and when have within that phrase exactly the same meanings as they do when used separately; the meaning of the phrase as a whole is a straightforward combination of the meanings of its components.
    – jsw29
    Commented Aug 19, 2022 at 15:56

5 Answers 5


The idiom "If and when X, (consequence)" has the meaning "if X happens, then when X happens, (consequence)". In other words, the "(consequence)" will not happen unless X happens, and will not happen before X happens.

It is generally used when talking about not making unnecessary preparations for an event that may not occur:

We'll come up with a zombie attack mitigation plan if and when we're attacked.

Some people might complain that "if and when" is redundant, because the "if" carries with it a sense of "when", in that you don't know whether X is going to happen until it actually does. But it's sometimes possible to know to some degree of certainty that something is going to happen, before it actually occurs - and in fact this is often the situation where the phrase is used:

We'll open fire on them if and when they open fire on us.

Simply saying "if they open fire on us" can invite the response "but we know they're going to, so we should fire now"; the when emphasises the speakers view that no pre-emptive action should be taken.

As to the difference between "if and when" and "when and if", the basic meaning is identical (as others have noted), but there is possibly a slight difference of nuance: the standard phrase is "if and when X", but inverting it to "when and if X" emphasises the if part, thereby putting more emphasis on the fact that it is uncertain whether X will actually occur.

  • I think "when" is this context means "at the moment when" (Given that this country will be invaded, we must be ready to fight. Furthermore, we must be ready to fight at the moment of invasion) rather than asserting the assumption (If he dies tomorrow, I will cry. --> When he dies tomorrow, I will cry)? yugioh.wikia.com/wiki/Missing_the_timing
    – BCLC
    Commented Jun 11, 2015 at 15:54
  • @BCLC: I'm not sure what you're saying. Can you clarify? What part of my answer (if any) are you referring to?
    – psmears
    Commented Jun 11, 2015 at 16:01
  • psmears, actually, I'm not quite sure I fully grasped your answer. Just skimmed it. Hehe. Anyway, sometimes people mean 'when' to assert the assumption in addition to specifying a condition. For instance, 'if I die tomorrow, you die with me.' The statement doesn't indicate any assertion that I will or have any reason to suspect with high probability that I will die tomorrow. However, if I somehow knew that I would die tomorrow and want to warn or threaten someone else, I say 'when I die tomorrow, you die with me' which I take to mean 'if I die tomorrow, you die with me. Also, I will die tomor
    – BCLC
    Commented Jun 12, 2015 at 11:13
  • Also, I will die tomorrow.' So what then do people mean when they say 'if and when' ? I offer an alternative interpretation of 'when' (I got the idea from Yu-Gi-Oh!) which is something like 'at the moment'.So 'when I die tomorrow, you die with me' under this interpretation is 'at the moment I die tomorrow, you die with me'. Previously, there was no indication of time so I could die tomorrow but you die 5 hours later. Under this interpreation, I die tomorrow and then you die a few seconds after.
    – BCLC
    Commented Jun 12, 2015 at 11:14
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    @BCLC: I don't think that your interpretation is actually very different from what I say in my answer - I already say the event "will not happen unless X happens, and will not happen before X happens" - the second part of that is more or less what you're saying, I guess :)
    – psmears
    Commented Jun 12, 2015 at 13:44

It's an idiom. You're not meant to analyze its component parts. That's what "idiom" means. ☺

If and when and when and if denote pretty much the same thing: something that's not as sure as "when", but more certain than "if".1 (Or, more cynically, it's just an overly-wordy way to say "if".)

I think there's a very slight emphasis on the first word: if and when is a teeny-tiny bit more conditional than when and if.

1 I did find one dictionary that supplied "if and when" as the US equivalent of UK as and when, which they define as "at the time that something happens". I'm not sure I agree with this: as a US English speaker, I perceive a slight but definite difference in meaning between "as and when" and "if and when".

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    As a UK speaker, "if and when" and "as and when" are different to me too :)
    – psmears
    Commented Jun 21, 2011 at 8:59
  • @psmears: I don't know anything about "as and when", but it sounds more plausible, since one can say "I will do X as Y happens", meaning at the same time as. It's a cousin to "when".
    – Ryan Reich
    Commented Jun 21, 2011 at 13:29
  • @Ryan: Both are common phrases, but "as and when" often has the implication (unlike "if and when") that the event may happen more than once (Some companies go through a recruitment process once a year, whereas others take people on as and when they need them) - hence my agreement with @Martha that their meaning is different :)
    – psmears
    Commented Jun 21, 2011 at 13:39
  • From my UK stance, "as and when" normally implies happening more than once, but it might only happen once, or (unexpectedly) never. Commented Jul 22, 2011 at 3:24
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    even though it's an idiom, it's perfectly acceptable to break it apart for analysis. that's how you get its inversion or similar corruptions/variations like if or when.
    – mendota
    Commented Feb 12, 2019 at 21:31

An "if" statement, "by definition," indicates the possibility or potential that an event may or may not occur. Whereas, adding "when" to a statement confers a strong sense of certainty that an event will occur:

e.g -- "If I die before I wake..." versus "when I die before I wake."

The former conveys the possibility death may occur while asleep, whereas the latter asserts the likelihood that death will certainly come [at some time] during slumber. Ergo, the very usage of the phrase "if and when" is either ambiguously contradictory or intentionally confusing, dependent, one supposes, on the intention of the user.

Respectfully, Dr. Jonas Moses

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    I have to disagree that the idiom is intentionally confusing or ambiguous. Rewrite it thus: "When X - if X happens - do Y." The sense is not of certainty but to clarify intent. No confusion is created. E.g.: "If and when I die in an accident, do not donate any of my organs" translates "if the cause of my death is accidental, do not donate anything of mine to science." It would be wrong to say when, since it might not happen; it is also wrong to only say if, because that does not clarify the timing. And, to use only if leaves my intent open to doubt in regard to other cases.
    – shipr
    Commented Oct 22, 2014 at 7:26

On the episode "Chasing Ghosts" of the television program NCIS, SSA Gibbs accuses Director Vance of conducting an off-the-books investigation into an assassination that resulted in his wife, Mrs. Vance, a bystander, also being shot to death. Director Vance denies SSA Gibbs' charge, saying, "No, not yet, but if and when I do, you'll be the first to know."

In the above context, it's clear that Director Vance is providing carefully delivered bravado. In a very legalese-like fashion, he is not committing to the certainty that he will do so with if, for that would be illegal, but is defiantly hedging the possibility, even probability, even probable certainty, that he will do so with when.

I find that if and when is often used in this way, almost like it's some kind of legal jargon, which it's not, that speakers who feel somewhat trepid about being intrepid fall back on—ostensibly to cover all their bases with if while really only using if to leave themselves a conditional out from the definiteness of a predicate that they'll insinuate in the same breath with when. Essentially, people tend to say if and when when calculatedly implying a certainty to the eventuality of a condition while not absolutely committing to that certainty but only its consequence. In a nutshell, people say if and when when they shy from merely saying when. It's as if if and when is in rhetoric a half-step beyond if but not a full step to when—a half-step and most often a half measure that sublimely feints strength but subliminally betrays weakness, which may be why so many so detest this phrase that only bravely boasts when after it has already cowardly mewled if.

Incidentally, if or when is definitively the better alternative, but people find using or to be less determinate than and and thus equivocating, so if and when is considered markedly stronger than if or when. This is rather ironic considering that using and between if and when creates a syntactical paradox whose impossibility renders the phrase and any ensuing sentence utterly meaningless when taken literally. While or allows either to be true, and requires both to be true, but if and when can't both be true because using if conditions that an event might not happen, whereas when predicates that that same event absolutely will happen. The word when precludes the possibility of if and vice versa, which makes it perfectly fine to use or but not and, at least not without departing from the literal for the idiomatic.


I've got a practical example for "when and if" that I'd like to subject to your thoughts:

The Save button will be enabled when and if at least one toggle button is on.

What I mean to say by that is that the button will remain disabled until one of the toggle buttons is turned on, and then remain enabled unless all toggle buttons are turned off.

Pure "if" doesn't say exactly when the button is enabled, while pure "when" doesn't ensure that the button may be disabled after it's enabled once.

I also think this is slightly different from "if and when" because we're starting from a "all toggles off, Save button disabled" standpoint and therefore "when" sort of happens before "if".

(Also thought of "when and while" as an alternative but I don't see it as being widely used, not sure if it's a real expression)

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