1a. No less than half the students failed the test.
1b. No less than half of the students failed the test.
Are these two sentences fine?
What is the meaning of ‘No less than half’?
Does it mean it is ‘more than half’?
2. He borrowed my car without so much as a by your leave!
What is the meaning of this sentence?
Is this sentence grammatically OK?
Thanks.
No fewer than…’, not ‘no less than…’ - you are referring to people in the plural (students).
I wouldn’t exactly call them ‘fine’ as there are better ways of expressing the same thing. It means half or more than half failed the test.
He borrowed my car without so much as a by your leave!
means
Her borrowed my car without asking.
‘Without so much as a by your leave’ is a common expression. It is correctly used.