How many morphemes are in the word 'disinterested'?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (B)

Morphemes are the smallest units of meaning in a word. In disinterested, you can break it down into prefix dis- (not), base interest, and suffix -ed (which turns interest into the adjective interested). Since interest + ed gives the word interested, the full breakdown is dis- + interest + ed, totaling three morphemes. That’s why three is the correct count. Note that semantically the word often means impartial, but morphologically it contains three meaningful pieces.