unpredictable
adj.adj. describing someone or something that changes often, so you never know what will happen next. It is hard to guess what they will do.
adj. tending to change suddenly or behave in ways that cannot be foreseen. Often modified by 'highly' or 'completely'.
The weather in the mountains is very unpredictable.
Investors are nervous because the stock market has been highly unpredictable lately.
The protagonist's unpredictable behavior keeps the audience in a state of constant tension, as his motivations remain obscured until the final scene.
From un- + predictable.
Often follows a linking verb like 'be', 'become', or 'seem'.
The result was unpredicted.The result was unpredictable.Learners confuse 'unpredicted' (something that was not foreseen in a specific instance) with 'unpredictable' (something that is impossible or difficult to foresee by nature).