Ineffectual means failing to produce the intended result or lacking the power to accomplish something. When efforts are ineffectual, they simply don't work, no matter how much energy goes into them.

Imagine a student trying to clean a whiteboard with a dry cloth. They scrub and scrub, but the marker smears instead of disappearing. Their cleaning is ineffectual: it doesn't achieve what they wanted. Or picture a teacher who makes rules but never enforces them. Students quickly realize those rules are ineffectual because nothing happens when they're broken.

The word often describes people, policies, or actions that seem weak or powerless. An ineffectual leader might talk a lot but fail to solve problems or inspire others to follow them. An ineffectual medicine doesn't cure the illness it's supposed to treat. An ineffectual argument fails to persuade anyone.

Notice the difference between ineffectual and simply unsuccessful: ineffectual suggests a kind of fundamental weakness or inability. A basketball player who misses a shot had an unsuccessful attempt, but an ineffectual player lacks the skills to compete at all. The word carries a sense that something was never quite capable of working in the first place.