Meaning
Conditional Clauses are a subset of Adverbial Clauses.
In Conditionals, the host clause features a potential scenario that that is applied only if the the situation of the embedded subordinate clause — the condition — is true. Often, the condition clause is something unreal, whether it’s a fantastical scenario that can never actually come true (but it just used for hypotheticals), a past event that could’ve happened but didn’t, or a possible future event. Other times, the condition clause is real and conveys an action that can and sometimes does happen (as is the case with zero-conditionals).
Conditionals are a type of cause-and-effect relationship. What sets them apart is that they are not indicative, meaning it’s not assumed that they actually occur in specific instances, but instead are dependent upon the reality of a situation.
Structure
The Condition Clause
In Conditional sentences, the subordinate clause is called the protasis, or the Condition Clause. It is the part that must first be true in order for the consequent host clause to also be true.
Condition Clauses begin with ‘if’ or some similar subordinator. The verbs of Condition Clauses are then backshifted, but only if the clause is unreal.
Subordinators
This clause begins with a subordinating conjunction that indicates the condition:
- ‘if‘ is the most common, and perhaps the default for Condition Clauses. It acknowledges that the condition may or may not happen.
- Other options with the same basic meaning include ‘as long as’, ‘given that’, ‘in the event that’, ‘on the condition that’, ‘provided (that)’, ‘so long as’, and ‘supposing (that)’.
- ‘unless‘ is the counterpart to ‘if’; it establishes an inverse relationship between the condition and the consequent. In other words, if the condition is not true, then the consequent is true.
- ‘whether or not’ and ‘regardless of whether’ are anti-conditional, calling attention to the fact that the consequent clause is not dependent on the protasis.
- ‘when‘ and ‘whenever’ are used to express that the condition does happen sometimes, but doesn’t identify any particular instance of doing so. Still, in those moments when they are true, then the host clause is also true.
- Unlike the rest of the subordinators, ‘when’ and ‘whenever’ establish a realis mood for their clauses.
If the clause features inversion, then it does not need any of these subordinators.
Backshifted Verb Phrases
When the Condition Clause is unreal, its verb phrase should be backshifted, meaning that the form of the verb is set one degree further toward the past than its actual meaning. i.e. We use present verbs for a future condition, past verbs for a present condition, and Past Present verbs for a past condition.
- Tenses should keep their aspects. For instance, a verb phrase that would otherwise be Present Continuous should be expressed in the Past Continuous form. In many cases, it’s only the leading auxiliary that changes its form in order for the entire verb phrase to be backshifted.
- Modal verbs backshift in a particular way. Can backshifts to could, may backshifts to might, shall backshifts to should, and will backshifts to would. If we need to backshift further, then they become Perfect Modals: could have, might have, should have, or would have.
Unreal protasis clauses can instead be expressed with subjunctive verb phrases (see Advanced Concepts below), but that practice is uncommon in modern English.
| Backshifting | |||
|---|---|---|---|
|
UNREAL |
REAL |
||
|
Past Meaning |
Present Meaning |
Future Meaning |
|
|
Past Perfect tense |
past tense |
present tense |
present tense |
When the Condition Clause is real (beginning with ‘when’ or ‘whenever’), its verb should not be backshifted.
The Consequent Clause
In Conditional sentences, the main clause is called the apodosis, or the Consequent Clause. The consequent is contingent upon the fulfillment of the Condition Clause.
When the apodosis is unreal, it should feature a modal verb at the start of the verb phrase, or else some modal substitute like ‘be going to’, ‘be expected to’, etc. or a modal adverb.
- Modal auxiliaries should be followed by a verb in its base form when the verb phrase is in the present, is in the future, or is not time specific.
- eg: “could visit”, “should wait”
- When the verb phrase is set in the past, we use perfect modals instead, meaning the modal auxiliary should be followed by ‘have’, and then a verb in the Perfect Participle form.
- eg: “could have visited”, “should’ve waited”
The default modal for a Consequent Clause is would (or will for future). Other modals can be used instead for different flavors of modality; for instance, should or ought to are best used for advice, can/could conveys potential, and must is either for obligation or deduction.
When the apodosis is real (where the linking subordinator is ‘when’ or ‘whenever’), no modal verbs are used.
The Complex Sentence
Order & Separators
The embedded Condition Clause usually comes either at the beginning or the end of the hosting Consequent Clause. It’s also possible to place the embedded clause in the middle of the host clause, as it is with all Adverbial Clauses — but for Conditionals, it often sounds awkward or convoluted, so a middle placement is quite rare. Whether the Condition Clause comes at the beginning or the end does not change the sentence’s meaning at all.
There must be some small partition between the two clauses. When the condition clause comes at the end, the linker (subordinating conjunction) can serve as that separator. When the condition clause comes at the beginning, we typically include a comma (when written) or a pause (when spoken) as the separator. For example:
- “I should go to the store if we’re out of milk.”
- “If we’re out of milk, I should go to the store.”
Declarative, Imperative, or Interrogative
The structure of the main clause determines whether the sentence as a whole is declarative, imperative, or interrogative; the Condition Clause remains the same either way. Here’s essentially the same sentence expressed in all three structures:
- declarative: “If I see Greta, I’ll give her this message.”
- imperative: “If you see Greta, give her this message.”
- interrogative: “If Bert sees Greta, will he give her this message?”
Notice that while the subject changes in each of the Condition Clauses, the word order does not change, nor are any words added or subtracted. The Consequent Clause, on the other hand, changes its structure each time in order to set the overall sentence as declarative, imperative, or interrogative.
Again, the Condition Clause can come at either the beginning or the end for all three of these variations.
Applications
Hypotheticals
The most common application for Conditionals is expressing unreal scenarios, whether they have the potential to happen in the future, or they’re impossible, or anything in-between. Conditionals are often divided up into the following categories:
- First Conditionals (“open”) express possible, perhaps even likely, scenarios, often for the future. They might convey plans (eg: “We’ll go to the museum next Saturday unless Charlie gets sick again.”), instructions (“If you’re trying to get to the highway, take the next left.”), warnings (“That dog might bite you if you get too close.”), and more.
- Second Conditionals (“remote”) express theoretical situations that are unlikely, or perhaps even impossible. They might be used for thought experiments (eg: “What would you do if you won the lottery?”) or to explain the state of things through contrast (“If Tanya tried harder, she probably could make the team.”), among other things.
- Third Conditionals (“past remote”) express counterfactual scenarios in the past, as if they belonged in an alternate reality. They might convey regrets (eg: “Had I known you were in trouble, I would’ve come to help.”), reprimands (“Frieda shouldn’t have operated that machinery given that she had no training.”), relief, and more.
There’s also the ‘Mixed Conditional’, for which the Condition and the Consequent occur in different time frames.
General Truths
The ‘Zero Conditional’ expresses cause-and-effect relationships that are generally true, rather than tied to a specific circumstance. These might be maxims or laws of nature. For example:
- “Water freezes when it reaches 0°C.”
- “If you climb to the top of the mountain, you can see for miles!”
- “Stanley gets grumpy if he hasn’t slept well.”
There are two differences in the form of Conditionals when they express general truths. First, they are the only type of conditionals that can use ‘when’ or ‘whenever’ as their linking subordinators.
Second, since they are not in the unreal mood, we do not backshift the verbs in the Condition Clause, and we don’t use ‘would’ for the Consequent Clause. In fact, we often don’t use any modal auxiliaries for the Consequent Clause, but it is sometimes beneficial to do us, like using ‘might’ to express uncertainty or inconsistency.
Relevance Conditionals
Sometimes the Conditional format is used for actions or states that are not actually dependent upon any conditions. For example, a waiter might say, “If you need anything, my name is William.” This is not a true Conditional because the waiter’s name is William whether the restaurant patrons need anything or not. What the waiter means is “In case you need anything, my name is William.”
These are called Relevance Conditionals because the Condition Clause (“if you need anything”) communicates that the listener may decide whether or not the Consequent Clause is relevant to them. They are sometimes also called Biscuit Conditionals, as in “I’ve left some biscuits on the countertop if you’d like any,” (in which case the biscuits are on the table regardless of the listener’s desire to eat any).
Relevance Conditionals usually feature present tense nouns in both clauses.
Advanced Concepts
Logic Statements
If and Only If
In logic contexts (like computer programing or certain levels of problem-solving), there is a difference between the terms ‘if’ and ‘if and only if’.
- In the case of “IF [condition] THEN [consequent],” the consequent will definitely happen if the condition first happens. But what if the condition doesn’t happen? In such cases, the consequent might still happen anyway, but it’s not guaranteed either way.
- In the case of “IF AND ONLY IF [condition] THEN [consequent],” (sometimes written as “IFF [condition] THEN [consequent]”) the consequent will definitely happen if the condition first happens; but if the condition doesn’t happen, then the consequent definitely won’t happen either.
In casual speech, ‘if’ is used ambiguously. If often means “if and only if”, but it may be unclear without further explanation.
Then
In logic, the counterpart to IF (or IFF) is: THEN. The term ‘then’ is regularly used at the start of the consequent statement, assuming that the consequent statement comes after the condition statement.
In casual speech, we can use ‘then’ to introduce the Consequent Clause, but only if the Condition Clause precedes it. For example, we might say, “If Tanya tried harder, then she probably could make the team.” This is optional and is often not used.
Inverse and Converse
When we rearrange a cause-and-effect relationship, we end up with the inverse, converse, or contrapositive.
- original: If A, then B.
- inverse: If not A, then not B.
- converse: If B, then A.
- contrapositive: If not B, then not A.
If the original statement is true, then so is the contrapositive, but the inverse and converse may or may not be. But if we specify “if and only if”, then the inverse and converse are also true.
The Subjunctive
Condition Clauses in the unreal mood have the option to be expressed with subjunctive verb phrases, which means they take the form of one or both of the following:
- BE (as a main verb) takes on either its base form (for a present meaning) or ‘were’ (for a past meaning) — ignoring subject-verb agreement — and is not accompanied by any auxiliary verbs.
- eg: “Let’s be on our guard, whether he be friend or foe.”
- eg: “If I were you, …” (instead of “If I was you, …”)
- The auxiliary verbs BE, HAVE, or should can be placed before their subjects while also replacing ‘if’ or another subordinator.
- eg: “Had she known better, …” = “If she had known better, …”
- eg: “Should you need anything, …” = “If you should need anything, …”
The subjunctive style is optional for Condition Clauses and depends on the preference of the speaker. But it is often considered formal or archaic and thus is rarely found in casual English.
Similar Adverbials
Concession Clauses
Concession Clauses are anti-conditionals: they call attention to the lack of a cause-and-effect relationship. For example, if one Conditional is “If my daughter cleans her room, I’ll give her ice cream,” a corresponding concession statement might be “Even though my daughter didn’t clean her room, I gave her ice cream anyway.” In sentences featuring concessions, all clauses are typically in the real mood.
Subordinating linkers for Concession Clauses include ‘although’, ‘(as) much as’, ‘despite the fact that’, ‘even if”, ‘even though’, ‘though’, ‘whatever’, and ‘while’.
Reason Clauses
Clauses of Reason are similar to Condition Clauses in how they establish a cause-and-effect relationship. The difference is that Clauses of Reason are indicative (a realis mood), meaning that they express what is known or assumed to happen. Therefore, sentences with Reason Clauses don’t use backshifting, and they might not include modal verbs.
A Condition Clause might become a Reason Clause if the situation turns from hypothetical to indicative. For example, “We’ll go to the park on Saturday if it doesn’t rain,” one week later might be “We went to the park last Saturday since it didn’t rain.”
Subordinating linkers for Clauses of Reason include ‘as’, ‘because’, ‘for’, ‘given that’, ‘now that’, and ‘since’.
Result Clauses
Clauses of Result are similar to Consequent Clauses in their meaning; both come true after a different clause in their sentence has come true. But Consequent Clauses are not subordinate clauses — they are usually the main clause of the sentence. Result Clauses are subordinate clauses. So while they two might mean similar things, they serve different roles in their sentences, and they have different structures, since one is subordinate but the other is not.
Subordinating linkers for Clauses of Result include ‘so [modifier] that’ and ‘such [noun] that’.
Infinitive Phrases
When expressing commands or suggestions, we can replace Condition Clauses with Full Infinitive Phrases. Consider these two sentences, which convey the same meaning:
- with a Condition Clause: “If you want to open the door, you need to find the hidden key.”
- with an Infinitive Phase: “To open the door, you need to find the hidden key.”
Infinitive Phrases can come at the beginning or at the end of the main clauses they’re embedded in.
Both Condition Clauses and Infinitive Phrases are used to communicate cause and effect. Infinitive Phrases in particular indicate purpose. They have many applications, but it’s with commands and suggestions that they overlap with Conditionals.
Teaching Tips
Explain Clauses
In many ELT curricula, Conditionals are among the first complex sentences that students learn. Therefore, they’re learning not only about Condition Clauses and Consequent Clauses, but also about how complex sentences work.
In order to be able to form complex sentences, students should first understand what clauses are. What makes a clause? What’s the difference between a main clause and a subordinate clause? Before diving into Conditionals, take the time to introduce or review the fundamentals of clauses for your students.
Limit the Subordinators
There are several subordinating linkers we can use for Conditionals. But leaners already have a lot to grapple with regarding the structure of these complex sentences. The first time you teach Conditionals, only use ‘if’.
The next time Conditionals comes through your curriculum, you’ll probably want to throw in ‘when’ and ‘unless’ into the mix.
It’s not until students have proven themselves to be comfortable with Conditionals (probably as they are nearing or have entered advanced levels) that you might want to introduce ‘given that’, ‘whether’, ‘as long as’, ‘whenever’, and so on.
Downplay 0th/1st/2nd/3rd
It is standard in TESOL to break apart this topic into pieces and teach 1st Conditionals, 2nd Conditionals, 3rd Conditionals, Zero Conditionals, and Mixed Conditionals. The problem with this method is that it expects students to memorize which modals and verb forms to use for each one; it gives students more to memorize rather than fostering an understanding of how these clauses work.
Insights to English recommends downplaying the different types of Conditionals and instead focusing more on whether the verb phrases are real or unreal. First, apply the tenses appropriate for the situation. Then, if the clauses are unreal, we backshift the Condition Clause and use modals for the Consequent Clause. This method is simpler and gives students less to memorize.
Insider Access
Visit our How to Teach Conditionals page on www.insightstoEnglish.com for a demonstrational video, bonus notes, printouts, a slideshow for your class, practice activities, and more.
Further Reading
Encyclopedia Pages
Insights Articles
- project: New Inventions
- project: Create a Choose-Your-Own-Adventure Story
Intermediate Topics
CEFR Levels B1-B2: Pre-Intermediate to Upper Intermediate courses
Complex Sentences
Verbals
Complex Sentences
Basics
Types of Subordinate Clauses
Adverbial Clauses
Comparison • Concession • Condition • Manner • Time & Place • Purpose, Reason, & Result
Content Clauses
Indirect Speech {Reported Speech • Indirect Questions} • Cognitive Expressions • Relief, Regrets, & Reprimands
