3.68 comparison of passive voice and ergative use

Note that ergative verbs perform a similar function to the passive because they allow you to avoid mentioning who or what does the action. For example, you could say 'Jane froze a lot of peas from the garden'. If you were not interested in who froze them but in what she froze, you could say 'A lot of peas were frozen', using the passive voice. If you were interested in how they froze, you could say 'The peas from the garden froze really well', making use of the fact that the verb is ergative.

For information about the passive, see 10.8 to 10.24.