Here's another little mental game I like to play. Take a look at this table:
| Suffix | Wh- | Th- | Assumed meaning of suffix |
| -en | When | Then | time |
| -o/ou | Who | Thou | person |
| -ere | Where | There | place |
| -ence | Whence | Thence | from a place |
| -at | What | That | a non-specific object |
| -ich/is | Which | This | a more-specific object |
It should be obvious that "Wh-" is a prefix that asks a question: "when" = "what time?", "who" = "what person?" (forgive the semi-recursive definition); and "Th-" is a prefix that points to an answer: "there" = "that place", "then" = "that time". So, the game is to find a pair of Wh-/Th- words with a common suffix, and then figure out what the suffix meant in Old/Middle English. And, of course, you don't want to use a dictionary to do this.
So, are there any others? I've taken care of "who", "what", "where" and "when", but the other two big questions ("why" and "how") don't seem to have obvious "th-" complements. The "th-" answer to a "how" ("in what manner") question is never "thow", it's "thus". But, how do "how" and "thus" come together ? And what about "why" ?
Whither/Thither – to a place
i have a subscription to the OED online, so of course i’m gonna use it. Both have early usages (thither 900 AD). Whither originally meant “to what place?” thither meant “to a place”
Why/Thy: When thy is not used in the possessive it means:
Thy: a. orig. By means or by reason of that, because of that, therefore. b. In relative sense: For the reason that, because. First usage in English under this definition 897 AD. Last usage 1275
Why/Thy: reason
OED defines these as:
Which/This: kind or quality
What/That: name or identity
Sorry I cheated. Fascinating stuff.
hah. sneaky little ‘thy’, hiding a second meaning from me.
Which/This: kind or quality
What/That: name or identity
ah… yeah, that makes more sense than what i wrote.