γραμματική ἐστιν ἐμπειρία τῶν παρὰ ποιηταῖς τε καὶ συγγραφεῦσιν ὡς ἐπὶ τὸ πολὺ λεγομένων → grammar is a practical knowledge of the usage of poets and writers of prose
strongly: P. and V. ἐρρωμένως, P. ἰσχυρῶς, ἐγκρατῶς.
energetically: P. and V. σπουδῇ, P. ἐντόνως, συντόνως.
vehemently: P. and V. σφόδρα, P. σφοδρῶς, Ar. and P. νεανικῶς.
attack vigorously (with words): P. πολὺς ἐγκεῖσθαι (dat.).