ἐν πέτροισι πέτρον ἐκτρίβων → by grinding stone against stones
cheerfully: P. and V. εὐθύμως (Xen.), ἡδέως, P. ἱλαρῶς (Xen.).
happily: P. and V. εὐτυχῶς, εὐδαιμόνως, μακαρίως.
readily, willingly: P. and V. ἡδέως, ἀσμένως, or use adj., P. and V. ἄσμενος, ἑκών, in agreement with subject.
