Monkeys can form sentences.
Monkeys can even speak in accents.
Now, they've gone one better by learning to recognize suffixes and prefixes.
According to stories in the National Geographic and the Washington Post about research published in the journal Biology Letters, Harvard researchers taught 14 cotton-top tamarins the linguistic rule of suffixes and prefixes.
Using the nonsense syllable "shoy" as the base word, they added prefixes and suffixes, such as "ba" and "ki." Then they played recordings of people saying these made-up words. One group of monkeys listened to words with prefixes; a second group listened to words with suffixes.
To test the monkeys, researchers played recordings in which half the words followed the pattern the monkeys had become accustomed to, and half broke the pattern. Here's how the Post described the result:
"When the tamarin turned his head at least 60 degrees toward the speaker, the researchers counted this as a response. The human equivalent would be if someone said, 'The girl edkick the ball,' and the listener cocked his head as if to say, 'What?' The tamarins responded 52 percent of the time after hearing a violation, compared with 37 percent for correct grammar."
That's better than some humans do with a high school education.