unless the poem has been expressly written in dialect. This disregard for the grammar of poetry and fiction is connected with another curious feature of English-language values: unlike speakers of ...

I shan't bother to go to the meeting at the school tonight - unless you want to go, of course. Note that in written English, as regards punctuation, the afterthought is usually preceded by a dash.

Just log off. Unless (he is) given sufficient warning of the consequences, he will continue to misbehave. However, this sounds quite formal and in spoken English we would normally keep subject ...