Create the ten forms of arcus. Although arcus happens to be masculine, remember that what we call 4th common nouns may also be feminine. Since the vowels + macron (long mark) are provided below, you should try to use them. The exercise will accept simple vowels, however. Click on the "Check" button to check your answers. Use the "Hint" button to get a free letter. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!