ineffective
adj.adj. not producing the result you want. You use this to describe a tool, plan, or person that fails to do their job properly.
adj. failing to produce the desired effect or intended result. Often used to describe systems, policies, or treatments that lack the power to achieve their goals.
The old heater is ineffective in this large room.
The new law proved ineffective because the government did not hire enough officers to enforce it.
Despite the high cost of the campaign, the marketing strategy remained largely ineffective at reaching the younger demographic the brand desperately needed to attract.
From in- + effective.
Often follows a linking verb like 'be', 'become', or 'prove'.
The medicine was uneffective.The medicine was ineffective.Learners often use the prefix 'un-' because of words like 'unaffected', but the correct negative prefix for 'effective' is 'in-'.