Only then can we know
Why is it, when using the construction ‘only then’, do we reverse the verb order that follows? i.e. We must acquire funding. Only then can we achieve our goals.
A friend suggested it was for emphasis, but I thought I’d put it to the masses, too. I had a student put this question to me and could not come up with a grammatical reason. Is it just ‘English is that way’? Does anyone know of any other situations where this occurs without a question? Is there a name for this?