Notes on the Conditional Sentences video
The hypothetical clause (protasis) is a dependent clause; the result clause (apodosis) is the main clause.
Either clause can come first.
When the result comes first, the linker (if, unless, when) before the condition separates the two clauses.
When the condition comes first, you need a comma to separate the clauses.
Unless = if not. For example, "She'll walk away unless you stop her" is the same as "She'll walk away if you don't stop her".
Other alternatives to if with similar meanings:
as long as
so long as
Alternately, you could use imagine, suppose or let's say to replace if when the condition clause is by itself (in these cases the result clause must come second, and you need a semi-colon to separate them, if not different sentences).
You can create similar cause-and-effect complex sentences (but not conditionals) with linkers like even though or although.
Would is often contracted to 'd in spoken form.
Would is rarely used in 1st Conditionals. It is, in many cases, the past form of will, so it usually doesn't make sense to use would for future meaning. But for unreal situations in the future, we could use other modals like should, could, or might.
In addition to affirmative sentences, you can use conditionals in negative, interrogative, and imperative sentences. In these cases, the result clause is the one that changes
affirmative: "You should call your mother if she's sick."
negative: "You shouldn't call your mother if she's sick."
interrogative: "Should your call you mother if she's sick?"
imperative: "Call your mother if she's sick."
The word then sometimes before the result clause (but after the comma) when the result clause follows the condition clause. This is more common in logic statements but less common in basic conversation.
2nd conditional is usually for present or near future. Unlikely events in the distant future could be expressed either with 1st or with 2nd conditional.
Here are some common usages for each type of conditional
Zero Conditional - rules, including rules of nature
1st Conditional - expectations, plans, threats, promises, etc.
2nd Conditional - warnings and close-calls
3rd Conditional - regrets and missed opportunities
The most common form of mixed conditional sentences are condition clauses from 3rd conditional and result clauses from 2nd conditional. But you can also do 3rd and 1st (respectively) or 2nd and 1st.
The second conditional sometimes uses "were" instead of "was" following singular subjects, as well as plural ones. This is called the subjunctive mood and is considered formal or even archaic.
Notes on the Backshifting video
Here's when we backshift:
to reference an action when its original context is now in the past (regardless of whether the action itself was/is in the past).
to express unlikelihood, impossibility, or uncertainty
in virtually every type of unreal situation.
as a polite request (as opposed to a forceful demand, which would use more confident words).
Since past simple gets backshifted to past perfect, did gets backshifted to had (and the main verb changes to the past participle form). [see the backshifting printout]
Multi-word modals get backshifted according to the first word of the modal:
is able to > was able to
have to > had to
are supposed to > were supposed to
[for more, see the backshifting printout]
There are only two reasons that you would change the main verb when backshifting:
There is no modal verb, as with a positive sentence backshifted from present simple to past simple.
You add have, in which case you need to change the main verb to past participle.
Shall backshifts to should. It's good to know, but since shall isn't terribly common anymore, we didn't include it in the video (although it is in our printout).
There are two ways to backshift must.
When must is used for deduction (present), it backshifts to must've (past).
When must is used for obligation (future), there is no direct backshift. However, since it means the same as have to or need to, it can backshift to had to or needed to (past).
Backshifting past to past perfect is sometimes ignored in casual English; you can keep it past simple or past continuous so long as it doesn't cause confusion.
For negative verb phrases, not always comes after the first auxiliary verb.
couldn't > couldn't have
wasn't > hadn't been
When you have verb patterns, ([verb] to [verb] - or - [verb] [verb]ing), the first verb is typically what backshifts, while the second verb (the verbal) remains the same.
- Conditionals table (letter) (A4)
- Modals page (coming soon)
- Backshifting chart (by tense: letter; A4) (by word: letter; A4)
Next in the Series
More on Conditionals
includes alternatives to 'if', subjunctive cases, inversion, different sentence types (+/-/?), and standalone condition clauses.
we'll get into the different modals, how they're used, how they change, and the differences between them