Choice of passive structures
We use passive structures when we want to talk about an action, but are not interested in stating who or what does/did it.
- Promises should be kept. (passive)
- Smoking must be banned. (passive)
- This house was built in 1990.
- The house is being painted.
Some verbs can be used in both active and passive forms with similar meanings. Examples are: to worry/to be worried; to drown/to be drowned.
Sometimes active and passive infinitives can be used with very similar meanings.
- There is a lot of work to do.
- There is a lot of work to be done.