Guide to Forming the Verb Phrase in Conditional Sentences

Factual Conditional Sentences: FORMING THE VERB OR VERB PHRASE

1. To express a future possibility or make a prediction

Condition Clause                               Result Clause
Present tense                                      will, can, should, could, may, might + base form
Present progressive tense
Present perfect tense

Examples:

If countries do not conserve their resources, they will regret it later.

If Andreas is telephoning me right now, he will get a busy signal.

*Note: A conditional sentence with the modal will expresses the strongest possibility, a prediction.  The
other modals indicate a lesser degree of possibility.

Examples:

If you have not bought your ticket, you may not get a seat.

If Mina is not attending class regularly, she could fail the course.

If the letter has not come by now, it might not arrive at all.

2. To express a general fact or a habitual action

Condition Clause                               Result Clause
Same tense                                          same tense

Examples:

If a caterpillar matures, it becomes a chrysalis. (fact)

Whenever my roommate studied late, I stayed up too. (habitual action)

*Note: When and whenever are often used instead of if to express a habitual action.

3. To make an inference

Condition Clause                                Result Clause
Present tense                                       must or should + base form
Past tense                                            must have + past participle

Examples:

If the store is already closed, it must be later than we thought.

If Nam really did lose his wallet instead of misplacing it, he must have felt very nervous.  

4. To give a command or instructions

Condition Clause                                 Result Clause
Present tense                                        imperative
Past tense
Present perfect tense

Examples:

If you miss the lecture, go to see the teacher.

If you missed the lecture, go to see the teacher.

If you have missed the lecture, go to see the teacher.


Hypothetical Conditional Sentences: FORMING THE VERB OR VERB PHRASE


1. To express a present or future hypothetical or contrary-to-fact situation

*Note: In the condition clause, when the simple past form or the past progressive form is used,
were is used for all forms of be.

Condition Clause                                          Result Clause
Simple past form                                          would, could, might + base form
                                                                    would, could, might + base form + ing
Past progressive form                                   would, could, might + base form
                                                                    would, could, might + base form + ing
Could, would + base form                            would, could, might + base form

Examples:
If I were you, I would save more money.
If Gabriel lived at home instead of in the dormitory, he would have a quiet place to study.
If Mona cleaned up her apartment every week, she would not always be complaining about how
messy it is.
If Sheila were not working in the dining hall, she could not afford college.
If Mike could find his library card, he would start his term paper.

*Note: In the example sentences above, were to + a preposition may be used for the simple past
form of the verb, as in If Gabriel were to live at home or If Mona were to clean her apartment
every week.

2. To express a hypothetical situation in the past
Condition Clause                                          Result Clause
Past perfect form                                          would, could, might + have + past participle
                                                                    would, could, might + have + been + base form + ing
Past perfect progressive form                        would, could, might + have + past participle
                                                                     would, could, might + have + been + base form + ing

Examples:
If Gail had turned her lab report in on time, she would have received the full ten points on it.
If Lana had not refused to lend us his car, we could have been driving to the beach right now.
Natasha might have enjoyed the movie if she had not been concentrating so hard on
understanding what the actors were saying.
If Carmen had been paying attention in class, he would not have been asking his friends how to
do the assignment last night.