Negative adverbs: never, seldom ever, hardly, rarely, not only, nor, nowhere.
Estos adverbios pueden abrir una frase para dar énfasis, y en ese caso se invierte el orden como si fuese pregunta:
I seldom work on Sundays - Seldom do I work on Sundays
She will never do that again - Never will she do that again
You will find this nowhere else - Nowhere else will you find this
I seldom visited her in those days - Seldom did I visit her in those days
We rarely drink after six - Rarely do we drink after six.
He insulted me and also took my car - Not only did he insult he also took my car.