General English Confusing Words Practice
Despite clear evidence that the messages were ordinary advertisements, he held the fixed ____ that they contained secret instructions intended only for him.
The stage mirrors created the ____ of an endless hallway, although the set was only a few feet deep.
The straight straw looked bent in the glass of water, but this optical ____ disappeared when she lifted it out.
He clung to the ____ that he could never lose money gambling, even after his bank statements showed years of losses.
Note
An illusion is a misleading appearance or impression, often involving what you see: a straight straw can look bent in water. A delusion is a false belief held despite evidence against it: someone may remain convinced that gambling guarantees a profit despite repeated losses. Illusion can also refer to a mistaken belief, so the words sometimes overlap; optical effects favor illusion, while a firmly held false conviction favors delusion.