The following might be standard textbook question, but not being a native speaker I am unaware of the origin.
In ancient English, as well as in other Germanic languages, questions were posed exchanging the position of subject and verb, a structure that still holds nowadays for auxiliary and modal verbs.
Examples:
- why speakest thou?
- how goes it?
whereas nowadays such ordinary verbs require the "do" as in "why do you speak?" and "how does it go?", respectively. Likewise for the negative forms, that used to be defined accompanying the verb with the negative not (as in speak not of the subject and similars).
When was the "do form" introduced in the English language (and how come)?
