ESL Library is now Ellii!

Unsupported Browser

Ellii may not function properly in Internet Explorer. We recommend using Google Chrome or Firefox instead.

Unsupported Browser

Ellii may not function properly in older browsers. We recommend updating yours to the latest version for the best experience.

How to Use the Conditional "Should"

July 6, 2017

Is it easy to learn the conditional mood in English? If only!

After English students learn the four types of conditionals with if-clauses and figure out when to use each one, they are told that there are other words and patterns to indicate the conditional mood, such as unless, even if, and should.

Students often struggle with the conditional should (also called should-inversion) for a few reasons. First, the pattern differs from other conditional patterns, and second, the meaning is unrelated to should as a modal of advice. It is also quite formal, so students don’t come across it all that often.

But much like any grammar target in English, the conditional should can be explained and learned fairly painlessly using patterns and examples.


Conditional should and modal should have very different meanings.

Students first learn that should is a modal of advice. The meaning of modal should is a suggestion.

  • You should pay attention in class.
    (I suggest that you pay attention in class.)

Conditional should means if and is used for hypothetical situations.

  • Should you need anything else, please call this number.
    (If you need anything else, please call this number.)


Conditional should and modal should have different patterns in English.

Modal should follows the typical S-V-O sentence pattern:

subject + modal + base verb

Conditional should has inversion in the sentence, which means that the subject and verb are switched. This is confusing for students because although inversion is common in questions, it rarely occurs in sentences.

The pattern of a conditional should sentence is:

modal + subject + base verb

Function Type Example
Modal sentence She should study for tomorrow’s exam.
question Should we study for tomorrow’s exam?
Conditional sentence Should you call after hours, leave a message.
question Should I happen to call after hours, is it possible to leave a message?

The patterns for conditional if and should are fairly similar, but note that if-clauses follow normal tense conjugation patterns with -s, -ed, etc., whereas conditional should takes a base verb (as modals always do).

Word Type Example
If sentence If he calls, please answer right away.
question If he calls, can you please answer right away?
Should sentence Should he call, please answer right away.
question Should he call, can you please answer right away?

Examples & Usage

The conditional should is a formal expression that we don’t use in speaking too often. It is more common to see in written form, such as in guidelines or regulations, on signs, or in legal documents.

  • Should anything happen, call this number.
  • Should the computer lock you out, try resetting the password.
  • Should you fail to comply with these regulations, you will be banned from the organization.
  • Should we be unable to reach our goal, we will try again next year.

The conditional should is most often used in place of the zero or first conditional. Remind your learners that the zero conditional is used for true facts or repeated actions, and the main clause is formed with a simple present verb. The first conditional is used when an outcome is likely or possible, and the main clause is usually formed with will + base verb.

  • If no one answers, please call back tomorrow.
  • Should no one answer, please call back tomorrow.
  • If I pass the test, I will graduate.
  • Should I pass the test, I will graduate.

It is possible, though not common, to use the conditional should in place of the second conditional when an outcome is unlikely or impossible. The main clause is usually formed with would + base verb. Remind students that the verb following conditional should must be a base verb (not a past verb).

  • If I were rich, I would travel around the world.
  • Should I become rich, I would travel around the world.


Not an Ellii member?

Get unlimited access to 1,000+ lessons and 3,000+ flashcards.

Sign Up

Comments (54)

Paloma (Guest)

Thanks so much! Very clarifying!

Reply to Comment

Tanya Trusler(Author)

You're welcome, Paloma! I'm happy to hear you found it useful.

Caleb (Guest)

I am a HUGE fan of this lesson, which rightly dispels misguided and condescending fear on the part of narrow minded ESL instructors of teaching the conditional Should with inversion. It is extremely common in literature, and since literature is a fundamental part of meaningful engagement in a language, training students to comprehend it, as well as the myriad contexts in which formal English is still the norm (legal contexts, advisory notices, official positions or simply formally disposed speech styles) opens doors to language learners and improves job prospects, since uses of such structures set aside the viable candidate from the passable one, especially in positions where public communication is integral to the role (even an administrative assistant must master these forms to advance pay grades). 100 thumbs up for the organization of the lesson...teaching should as a modal of advice first and then getting into conditional declarative uses. I will closely follow this scheme (though I'll substitute more colourful usage examples) in my own lessons on conditional structures.

Reply to Comment

Tanya Trusler(Author)

Hi Caleb,

Thanks a lot for your message! I'm happy to hear you found this post useful. I think that it's great to expose higher-level students to all the structures they will see in the language. Some teachers might just be wondering when the correct time to do so is (so as not to overwhelm lower-level students with complicated constructions that they won't see at those levels).

Caleb (Guest)

I was highly appreciative of this excellent lesson on the use of should as a conditional marker in conditional sentences using subject verb inversion.

All to often, ESL teachers exaggerate the difficulty of the use of were, should and had in SV inverted constructions of conditional sentences and, in my opinion, greatly underestimate the learning capacity of their students in so doing -- not to mention the consequences of closing doors of comprehension on a form that is ubiquitous in literary works, newspaper articles (NYT opeds frequently deploy advanced vocabulary and formal grammatical constructions), journals, legal documents, advisory notices from businesses to customers, employees or tenants, a large variety of professional communication in so standard a phrase as 'should you have any further concerns, do not hesitate to contact our offices, [hours of operation or contact info],' and last but not least, persons of a formal, academic or professional bent who regularly or in certain key settings deploy these structures in speech.

The particular organization of this lesson, firmly establishing the use of should as a modal of suggestion/advice/obligation before moving on to the conditional usage of should, is one I find particularly effective. I especially like the inclusion of interrogative (question) sentence examples and negative statements. In my own lessons on conditional sentences, I plan to follow this organization...though I can't decide if it would be good to group had, were and should together in a single unit on SV inversion in conditional sentences. Any advice on that idea would be appreciated.

I also think it's very important for higher level intermediate students, and adult learners trying to improve writing skills, to also learn the effect of register that the use of these forms has in relation to other constructions (such as non-inverted SV conditional sentences using 'if').

Reply to Comment

Tanya Trusler(Author)

Thanks again, Caleb. It's great to have a list of places that you'd commonly see the conditional should in context, so thank you for listing those in your second paragraph. I think adding had and were to the mix and teaching them alongside should (for conditional sentences with S-V inversion) is a great idea for higher-level students. I'm a firm believer in presenting related things at once so that students can see the bigger picture. In my experience, it provides a greater understanding of the patterns etc. (You'll see I advocate for presenting all four conditional 'if' patterns at once in my post on Conditionals: Thanks again for taking the time to comment! Best of luck with your lesson.

Craig Senior(Guest)

Although it is grammatically possible, for a conditional marker, I suggest using 'if' instead of 'should,' because 'if' is immediately understood as a conditional, whereas with 'should' the reader or listener doesn't know what was meant until the end of the clause after the comma. It requires a moment to process.

With oral consumption, we want the audience to understand, left-to-right, without having to retain or return to the start of the sentence to understand the intended meaning.

Reply to Comment

Tanya Trusler(Author)

Hi Craig,

I agree! The conditional should is quite formal and not heard very often. We should encourage our students to use 'if' when speaking and writing, though we do need to introduce the conditional should to higher-level learners in case they come across it.

Mariya (Guest)

Hi, Tanya!
Thank you for this lesson.
I have one question though. Is it right to use a conditional should in the second part of a sentence instead of first (as provided in examples above)? Namely, is the following sentence correct: 'Let me know should you have any questions'?
Many thanks!

Reply to Comment

Elie C.(Teacher)

In accordance with what Mariya says, i have seen in a grammar book the following sentence :
"We were so happy that we should have liked to stay there for ever".

It's a french grammar book, there may be some mistakes. In your opinion is that sentence correct ? Is this perhaps a little old-fashioned ?

Also i've seen this other sentence, that seems even stranger to me :
"If you should need our help, you know that you can depend on us".

So "should" can also be used to form a subjunctive ? Maybe it is not so much used ? I've never seen that before.

Thanks a lot !

Lisa B.(Teacher)

Wonderful information!
Please consider putting this in an easy to print format. I would love to have this with me as a reference and I also would welcome using it with my advanced students. I work with adult English Language Learners who are either employed or looking for employment.

Reply to Comment

Tanya Trusler(Author)

Thanks, Lisa! If you're a subscriber, you can find a one-page printable chart with the information from this post here:

We love giving back to the ELT community, and that's why our blog is free and full of grammar explanations and fun activities. But we are a small company of hardworking, full-time employees, so we can't give it all away for free, unfortunately! You can access more than 1,000 lessons and resources and 3,000 flashcards for as little as $7/month. If you're interested, find out more here:

Slamet Widodo(Guest)

Great lesson.
Conditional sentence is one of grammar horror in my student days back then. I'm an Indonesian and English isn't familiar for us compare to our neighbors Singapore and Malaysia.
Understanding conditional sentence needs higher level of culture understanding and it even getting worse should we incorporate the simplicity of conditional sentence in Bahasa Indonesia (Indonesian language).

Regarding this, I want to ask you about the right way of constructing conditional sentence using should.

We can still enjoy our daily life should we be able to keep the enemy at bay.

Is the main claus and the conditional clause constructed rightly?
Should aforementioned example is not correct, what is the correct one for main clause and/or conditional clause?

Thank you very much.

Reply to Comment

Tanya Trusler(Author)

Hi Slamet, your sentence is correct! I agree that grammar targets that don't translate directly into one's native language are very difficult. This post and chart on conditionals might also help you:

Mehdi Roostaie(Guest)

Very good,concise and useful explanation. Thank you.

Reply to Comment

Tanya Trusler(Author)

Thanks for the kind words, Mehdi!

Melisa Peralta (Guest)

Estoy realizando un trabajo y tengo algunas dudas.. podrán ayudarme por favor? 🙏
Qué tipo de modal es? 🙏

Reply to Comment

Ricardo Barbosa(Guest)

Would this phrase be a FIRST CONDITIONAL one?

El Ayoubi M.(Member)

Thank you!

Reply to Comment

Tanya Trusler(Author)

My pleasure!

Leave a Comment

Log In to Comment Reply

Comment Reply as a Guest
  • **bold**_italics_> quote

    This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

    Thinking of joining Ellii?

    Complete this form to create an account and stay up to date on all the happenings here at Ellii.