A te incipiat cogitatio tua et in te finiatur, nec frustra in alia distendaris, te neglecto.
Meliboeus decides the contest in favour of Corydon:-- Haec memini, et victum frustra contendere Thyrsin.
Frustra vitium vitaveris illud, / Si te alio pravus detorseris=--In vain do you avoid one fault if you perversely turn aside into another.
Frustra fit per plura, quod fieri potest per pauciora=--It is vain to do by many agencies what may be done by few.
Frustra laborat qui omnibus placere studet=--He labours in vain who studies to please everybody.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "frustra" in a variety of sentences. We hope that you will now be able to make sentences using this word.