The above is a screenshot of Collins Cobuild dictionary explaining the word 'runway'. What bothers me is the definite articles in phrase "the runway is the long strip". Why can't it be just " the runway is a long strip" or "a runway is a long strip" ? Kindly help. Thanks in advance.
closed as off-topic by FumbleFingers, David, tchrist♦ Jul 31 '17 at 14:33
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Please include the research you’ve done, or consider if your question suits our English Language Learners site better. Questions that can be answered using commonly-available references are off-topic." – David, tchrist
Once you establish the setting of an airport, it is correct and natural to use definite noun phrases for anything commonly found at an airport, such as
the control tower
the parking lot
the flight attendant lounge
the fence around the airport
This is because most airports have these things, just like most houses have front doors, walls, stairs, gardens/yards, etc.
As for the long strip of ground with a hard surface, this is also something that the reader can be expected to be able to "identify." For instance if you are looking at an airport from the sky, it's pretty easy to identify it. You could even use the hard surface, but by using a hard surface the sentence is not concerned with whether you can "identify" which hard surface it is; in this case it is similar to saying "any hard surface." On the other hand, you could use a long of ground with a hard surface, but it sounds better to be more definite when, um, defining something.
Note that the sentence says "an aeroplane" because most airports service more than one aeroplane. Here an is similar to one.