You need to say your sentence immediately after the command. So if you want to write “sorry” in the chat, you need to say “Start writing sorry”, without any pauses.
This goes for all your unrecognized commands.
Since DRE cannot compare your sentence with any existing command it already knows, it relies on Microsoft Speech Recognition services which is less than optimal. This may be why it often misinterprets your input for these types of commands.
It’s recommended to add your own commands in case you often write certain sentences.