Someone (short for someone) once said, "..."
A proverb says, "..."
As the saying goes, "..."
There are other sentences that are not commonly used, which are also listed as follows.
1) A great scientist/poet, (name can be added here), once said …… A great scientist/poet once said, …
2) "Genius is 2% inspiration and 98% perspiration" is Edison's view. This sentence has been repeatedly confirmed by more and more people. "Genius is 2% inspiration and 98% sweat" is Edison's view, which has been repeatedly confirmed by more and more people.
3) Many years ago, a great philosopher said … Many years ago, a great philosopher said …
There is an English proverb that says "easy come, easy go". There is an English proverb that says "easy come, easy go".
5) There is an old saying, "Practice makes perfect." This is the experience of our ancestors, however, even today, it is still correct in many cases. As the saying goes, "Practice makes perfect". This is the experience of predecessors, and it is also applicable in many cases today.
As a popular proverb says … as a popular proverb says …
7) A great writer said: ... A great writer once said.
Famous sayings are the same as normal sentences, as long as the first letter of the sentence is capitalized.