Parts of Speech
Did you ever see a speller ask for the part of speech in the Scripps National Spelling Bee? They ask that question for a reason. In a moment, you will see the benefit of asking for the part of speech. Here are some tips and tricks with parts of speech.
When theres an "us" sound at the end of the word, ask for it's part of speech. If it's an adjective, then it is always spelled with an -ous. Examples: serendipitous, ambiguous, ambitious, auspicious, barbarous, callous, capricious, chivalrous, courageous, decorous, efficacious, ect.
When it's a noun and it has the "us" sound at the end of it, then it's probably a -us or a -os, such as rhinoceros, or celcius.