happen

I have this question about the use of the verb happen. Which of the following are correct:

1. What happens when the contract will be expired?

2. What will happen when the contract expires? 3. What happens when the contract expires?

4. What does it happen when the contract expires?Also, can I use happen like this?

5. I don’t happen to be a teacher.

In your first four listed examples above, Ruben, you are referring to future time, but only 2 and 3 are grammatically correct.

Let’s look at the arrangement of structures in your second sentence.

When behaves like if in subordinate clauses of this kind and remains in the present tense when we are referring to a future condition. Consider the following:

• 'What will happen when the contract expires?'
• 'What will happen if I get home late?'
• 'What will you do if I don’t return till Thursday?'

Let’s look now at the arrangement of structures from your third sentence. If we are discussing a general truth, rather than a specific instance or event, the main clause usually remains in the present tense as well as the tense in the if or when clause. Consider the following:

• 'If the roads are icy, I stay at home.'
• 'What sort of clothes do you wear when the temperature falls below -15 C?'
• 'What happens in this company when male staff request paternity leave?'

However, in your example, Ruben, we can use the present tense in both clauses to refer to a future event. It is clear that you are talking about your specific contract because you refer to it as ‘the contract’. (If you had said: ‘What happens when contracts expire?’ you would be discussing general truths.)

For your fourth sentence, remember:

no does/do/did when what/who question refers to the subject.

When 'wh-' questions, like what, who or which, refer to the subject of the sentence, we do not use the auxiliary forms do/does/did. These auxiliaries are used only when the wh-question refers to the object. Compare the following:

• 'Which animals rear their young in nests?' 'Squirrels rear their young in nests called ‘dreys’.'
• 'Which animals did you see on safari?' 'We saw lions, leopards and tigers.'
• 'Who saw the accident?' 'I saw it.'
• 'What did you see?' 'I saw the car collide with a bus.'

The exception to this rule is if you wish to use do/does/did for emphasis when what/who/etc questions refer to the subject. Thus, normally, we expect to hear:

• 'Who earns more than a hundred grand a year in this company?' 'The Chairman earns £150,000.'
• 'What happens when the contract expires?' 'Under normal circumstances, it’s renewed.'

But if the answer is not known and we wish to emphasise the question in a particular way, use of the auxiliary would be appropriate. Thus:

• 'Well, what does happen when your contract expires? Does anyone know?'
• 'Well, who does earn more than a hundred grand in this company? Does anyone?'

Four fifth sentence happen can be used with a following infinitive to suggest that something may happen by chance. Consider the following:

• 'If you happen to see my father, ask him to ring me at home later this evening.'
• 'If you happen to need any help with the decorating, don’t hesitate to ask me.'

'In your example, the context for your statement might be the following:

• 'I don’t happen to be a teacher, though I sometimes give lessons to help out.