After posting the homework online, she received a flurry of support from fellow academics – who also did not know what the clause was.
The question read: "There's a lovely example of a fronted non-finite clause on the bottom half of page 45. Can you find and copy it?"
Alongside the photograph, she wrote: "Oh dear. Trying to help the nine-year-old with homework again..."
She said: "It's nonsense on a stick... there's no evidence to suggest that learning these esoteric labels for parts of a sentence helps children reading or writing."
A non-finite clause is one which contains a verb which does not show the tense, meaning it does not show the time at which something happened. The "fronted" element means the clause appears at the beginning of the sentence.
An example might be the phrase at the start of the sentence: "To catch the robber, the police put up a wanted poster."
In response to the post, many said they were left baffled. Author James McEnaney said: "I'm an English teacher and a journalist and a published author and am 100 per cent convinced that this stuff is utterly pointless."
A critic said: "I'm a professional writer and editor of linguistics materials with a Masters in Applied Linguistics, and I have absolutely never needed to know what a 'fronted non-finite clause' is."
Another added: "Professional editor here. No idea what that is or why a child would need to know it."
Following the support, Professor Roberts said the requirement for children to learn such tricky grammar was "nonsense".
She added that "real homework" should be "finding bugs in the garden, growing vegetables, cycling and climbing trees".