[speak for someone/something] to represent the feelings or opinionsof another person or group of peopleI know I speak for us all when I say how sorry I am for this mistake.
speak off- to speak without preparing a speech;to render a spoken opinion or estimate. she is capable of making sense and being convincing even when she speaks off
speak up- to speak in a louder voice so that people can hear you:
Could you speak up? We can't hear at the back.
speak on- to talk about a particular
topic.
What will you speak on
today?
