ABSTRACT
7.11. In 'first-words'. (i. e. the first parts of compounds; cf. 2.3) the singular as a rule is used even if the idea is plural. The chief reason for this phenomenon is that in the oldest stratum of compounds the uninflected stem was used with no indication of case or number, and new compounds would at all times be freely formed on their pattern. In another (later) type of compounds the genitive plural was used, but as this ended in OE in -a, which later became -e and then was dropped, the form came to be identical with, the nominative singular. Thus ModE book-reading may be equally a continuation of OE bōca-rǣding and bōc-rǣding which are both found. (OE bēc-rǣdinge in Bede is quite exceptional). — Cf. p. 499,
