Prepositions (before nouns)
Some nouns form fixed combinations with certain prepositions if used in specific contexts:
| Example (1): | Sound at a distance of 400 metres downwind is virtually inaudible. |
| ‘… at a distance …’ | |
| Example (2): | We measure noise at all different frequencies. |
| ‘… at frequencies’ | |
| Example (3): | Wind speeds must stay at levels of around 6 to 8 m/s. |
| ‘… at levels …’ | |
| Example (4): | Noise levels are averaged at a wind speed of 5 m/s. |
| ‘… at a speed …’ |
Notes
Use ‘at’ to form a prepositional phrase with the nouns
- ‘distance’, as in Example (1),
- ‘frequency’, as in Example (2),
- ‘level’, as in Example (3),
- ‘speed’, as in Example (4)
More examples
| Example (5): | It’s important to get the parts in time. |
| ‘… in time’ | |
| Example (6): | We’ll have to take the generator off line. |
| ‘… off line’ | |
| Example (7): | We give planning permission on (the) condition that criteria are met. |
| ‘… on (the) condition …’ | |
| Example (8): | We observed operation on a morning with wind speeds around 9 m/s. |
| ‘… on a morning …’ |
Use the specific prepositions with nouns such as:
- ‘in time’ or ‘on time’, meaning ‘punctually’, as in Example (5),
- ‘off line’, meaning ‘not operative’, as in Example (6),
- ‘on (the) condition’, meaning ‘provided that’, as in Example (7),
- ‘on a morning’, when referring to the first half of a day, as in Example (8),
but ‘in the morning’, referring to any morning, - also: ‘in the afternoon/evening’,
when referring to the second half of the day.