Now, the processes that change _fall_, _ox_, and _goose_ into _fell_, _oxen_, and _geese_, inasmuch as they cease to operate on the language in its present stage, are obsolete processes; whilst those that change _move_ into _moved_, and _horse_ into _horses_, operating on the language in its present stage, are vital processes. A definition of the word irregular might be so framed as to include all words whose forms could not be accounted for by the vital processes. Such a definition would, in the present English, make words like _bent_, _sought_, &c. (the euphonic processes being allowed for), regular, and all the strong verbs irregular. The very fact of so natural a class as that of the strong verbs being reduced to the condition of irregulars, invalidates such a definition as this. II. _Processes of necessity as opposed to processes of habit._--The combinations _-pd-_, _-fd-_, _-kd-_, _-sd-_, and some others, are unpronounceable. Hence words like _step_, _quaff_, _back_, _kiss_, &c., take after them the sound of _-t_: _stept_, _quafft_, &c. (the _sound_ being represented), being their praeterites, instead of _stepd_, _quaffd_. Here the change from _-d_ (the natural termination) to _-t_ is a matter (or process) of necessity. It is not so with words like _weep_ and _wept_, &c. Here the change of vowel is not necessary. _Weept_ might have been said if the habit of the language had permitted. A definition of the word irregular might be so framed as to include all words whose natural form was modified by any euphonic process whatever. In this case _stept_ (modified by a {338} process of necessity), and _wept_ (modified by a process of habit), would be equally irregular. A less limited definition might account words regular as long as the process by which they are deflected from their natural form was a process of necessity. Those, however, which were modified by a process of habit it would class with the irregulars. Definitions thus limited arise from ignorance of euphonic processes, or rather from an ignorance of the generality of their operation.