Both sentences are incorrect. The verbs do not agree with the subjects. It appears they were written by a non-native English speaker. Here's what they should be: 1. They are richer than they appear. 2. The really serious cases are fewer than have been suggested.

Thank you, Nancy. So where should I put the implied subject “it” in the sentence? “than it has been suggested”? Or “than has been suggested by it”? And what does it refer to?

Sentence one is incorrect, as Cullen writes. Sentence two is fine, in my opinion. Even though "than has been suggested" doesn't have a subject, the subject "it" is implied.

Hi. Thank you. But I don’t see why the part “... than has been suggested" would work. Since there’s no subject between “than” and “has”, we cannot decide which word to choose between “has” and “have”. I would just say “There are fewer very serious cases than suggested". Does it make sense?

Hello, I would say " They are richer than they appear" or "They are richer than it appears", depending on what the writer is trying to say. Also, "There are fewer very serious cases than has been suggested" sounds much better. Message me if you have any other questions 😄