The English language is notorious for having many pairs of words that are very similar in spelling (though not necessarily in pronunciation) but very different in meaning. It’s worth your efforts to spend some time looking at those confusing pairs, and making sure that you can spell and use each of them correctly. Here are three word pairs that commonly cause problems, even for native English speakers:

• vicious and viscous
• allusion and illusion
• marital and martial

Vicious (VIH-shuhs) is an adjective that means cruel, brutal, aggressive, and often violent. Viciously is the adverbial form. The word comes from the Latin word for “vice.” A vicious act is one that is meant to deliberately cause harm.

The word viscous (VIHS-cuss) means sticky and thick, and generally refers to a substance that is thicker than liquid, but not quite solid. Tree sap, honey, and tar are all things that have a viscous consistency when they are warm.

Example: After seeing photos of birds struggling in the viscous slick of oil, people living on the coast made vicious verbal attacks on the employees of the petroleum company who were working in the area.

An illusion (ih-LOO-zhun) is a incorrect perception about something; that is, you think something is true because of what your senses – your eyes, your ears, or your beliefs – tell you, but actually it is false. An auditory illusion might be that you imagine you hear whispering voices, when it’s only the breeze rustling the leaves in the trees.

When you make an allusion (ah-LOO-zhun) to something, you are referring to that thing, but not mentioning it directly. Allusions generally refer to aspects of shared culture, such as books or movies, that the listener is assumed to know. For example, you might make an allusion to “changing water into wine,” the first miracle attributed to Jesus, but it would only be meaningful to someone else who was familiar with the Bible.

Example: As we reached the top of the mountain after a five-mile hike in the hot sun, Jerry said, “Look! Palm trees just ahead!” in an allusion to the oasis in the desert that appears as an illusion caused by heat waves, fooling thirsty travelers.

If you are in a marital relationship, that means you’re married to another person. If you’re in a martial relationship, it means you’re fighting with another person. We certainly hope you won’t mix these two words up! Marital (MAIR-ih-tuhl) means “pertaining to marriage.” Martial (MAR-shul) is a word that comes from Mars, the Latin god of war, and is used in connection with things that pertain to the military, to war, or to soldiers.

Example: Ellen and Dave chose to have Tchaikovsky’s “1812 Overture” played at their wedding, complete with cannon fire, which seemed to be a strangely martial way to begin their marital life.