ineffective
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ineffective
Without achieving the intended effect, or any noticeable effect at all; ineffective or futile.
Alle seine Versuche, das Feuer zu löschen, blieben wirkungslos.
All his attempts to put out the fire remained ineffective.
The adjective has a simple structure: it consists of the noun 'die Wirkung' (effect) and the suffix '-los' (-less), which means 'without'. So 'wirkungslos' (ineffective) literally means 'without effect'.
Leider war das neue Medikament bei ihm völlig wirkungslos.
Unfortunately, the new medication was completely ineffective for him.
'Wirkungslos' (ineffective) is very often used with the verb 'bleiben' (to remain). The construction 'wirkungslos bleiben' (to remain ineffective) emphasizes that an expected effect did not occur.
Trotz der vielen Proteste blieben die Appelle der Bürger wirkungslos.
Despite the many protests, the citizens' appeals remained ineffective.
The word often describes things from which one had hoped for an effect. Typical combinations are 'wirkungslose Maßnahmen' (ineffective measures), 'wirkungslose Medikamente' (ineffective medications), or 'wirkungslose Versuche' (ineffective attempts).
Sein Versuch, sie zu überzeugen, war leider wirkungslos.
His attempt to convince her was unfortunately ineffective.
effective
'effektiv' and 'wirkungslos' are clear opposites. 'effektiv' means that a measure achieves its goal or really helps. 'wirkungslos' means that no noticeable or desired effect occurs. Both words are often used with methods, rules, medications, or measures. If something helps, it is effektiv. If it does not do anything, it is wirkungslos.
Die Salbe blieb wirkungslos, deshalb ging Maria zum Arzt.
The ointment had no effect, so Maria went to the doctor.
Kurze Pausen sind beim Lernen oft sehr effektiv.
Short breaks are often very effective when studying.