Before we continue with what this chapter really is about, pronouns, we have to make a small loop to discuss a related phenomenon: The pronominal adverb.
The pronominal adverb, or 'pronoun adverb', is not a complete novelty to English speakers:
" _Whereof_ one cannot speak, _thereof_ one must be silent"
--Ludwig Wittgenstein
"I know a bank _whereon_ the wild thyme blows"
--William Shakespeare
We use it in modern English too:
"I am _herewith_ sending you the details of your order."
" _Therefore_, we decided to postpone the project."
The mechanism
_Whereof_ is another way of saying 'of which'. _Herewith_ is 'with this', _therefore_ is 'for that', and so on.
If the pronoun _what/which, this,_ or _that_ is preceded by a preposition (of, by, for), we can replace the pronoun by the adverb _where, here,_ or _there_.
Note that we can only do this to pronouns that refer to inanimate things, not to persons.
_Which/what_ turns into _where_:
whereof | of what
wherewith | with what
_This_ turns into _here_:
hereon | on this
hereby | by this
_That_ turns into _there_:
thereof | of that
therefore | for that
On the next page, we look at the Dutch pronominal adverbs.