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Notes on the Forming Verbs in 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:

    • supposing

    • provided (that)

    • given that

    • 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 shouldcould, 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.

Related Printouts

  • Conditionals table (letter) (A4)
  • Modals page (coming soon)
  • Backshifting chart (by tense: letterA4) (by word: letter; A4)

Next in the Series


details on how verbs (including modals) get shifted backward

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

sentence structureErik Arndt