[Copied from xchat-gnome/src/common/text.c] 

static char * const pevt_chanhop_help[] = {
        N_("The nick of the person who has been halfop'ed"),
        N_("The nick of the person who did the halfop'ing"),
};

[End of copy]

I am not completely sure because I don't know where these strings are used and for what, but I think they explain the meaning of $1, $2 in textevents.h:
{"Channel Half-Operator", pevt_chanhop_help, 2,
N_("-%C10-%C11-%O$t$1 gives channel half-operator status to $2")},

If so, the strings in the static char const above must be swapped.

And there are four "the person of did" that should be "person who did"

I am trying to make a patch with these corrections and adding some ...the person "who" did something to smooth expressions used.