5. Conditional Clauses: The Invention of the LAS

In the previous section, you learned about the Launch Abort System (LAS), which, after being activated, saved the astronauts´ lives. Now imagine you can travel in time and now you are several years back in the past. In 2010, a scientist spoke about the invention of the LAS system when commenting on the two slides in Task 6 on p. 21 in your coursebook. The slide on the left shows an existing safety system for aircraft, while the system on the right-hand side, called a LAS system for spacecraft, did not yet exist in 2010. Listen to the lecture given on both these systems (Recording 08 that comes with your coursebook) and complete this overview. Alternatively, you can read the transcript on p. 119 in your book.

Here are similar examples of conditional clauses from the previous task. Compare them:

 

We use the first conditional when the situation is real or possible:

If an aircraft fails, the pilot will activate the ejection system.

If + subject + Present Simple, subject + Future tense

subordinate clause , main clause

You can also change the order of sentences, but you will not need a comma then:

The pilot will activate the ejection system if an aircraft fails.

 

 

We use the second conditional when the situation is imagined or impossible:

If a spacecraft failed, the computer would activate the LAS system.

If + subject + Past Simple, subject + would + bare infinitive

subordinate clause, main clause

You can also change the order of sentences, but you will not need a comma then:

The computer would activate the LAS system if a spacecraft failed.

 

Three important notes:

  • In the first conditional, there is never the Future Tense in the if-clause. The Present Tense is used instead.
  • In the second conditional, there is never “would” in the if-clause. The Past Tense is used instead.
  • If you compare the two types of conditional sentences, you will see that the second conditional is similar to the first conditional, but the tenses are shifted one time level to the past.

To find out more about conditional clauses, study this overview of basic conditional clauses. Now, it is time to practise this new grammar point. Do it first in general English context by completing these tasks:  A, B, C, D. Then practise the same grammar point in technical English contexts by completing tasks E, F from your book.