Just what is a “fronted adverbial” anyway? Quite simply, it’s a word or self-contained phrase at the start of the sentence, that describes how the action in the rest of the sentence happens. You might ...

Others complained that Year 6 pupils are too young to be learning the complexities of fronted adverbials,. One person said: "We need a better way of teaching this stuff.

So here, 'earlier today' is a fronted adverbial. Here are some more examples. Calmly, the family sat together and watched a movie. Like a cheetah, Bill sprinted to the finish.