Comparative, this is bigger THAN that, you are nicer THAN her.
The correct use is actually "different from". However, you will find "different than" commonly being spoken across the US. This does not mean it is correct.
Always use use from with differ. "This is different from that. " Never use than with differ.
You would say "She is older than her." "Her" is the correct pronoun to use in this comparison.
Have or Show empathy would be more correct than Use empathy.
Yes, of course.
Younger than me is correct.
"Younger than you" is correct. This is the standard way to construct comparative phrases when comparing ages.
Liz will use a CD-R compact disk to write to more than once. Carlo will use a CD-RW compact disk to write to more than once. Who is using the correct disk for its purpose?
We used "were" when we are talking about more than 1 person. We used "was" when we talk about single person
Different from is correct. Different than is not correct, although it is very common The mistake is made by analogy with the comparative form, which does use than. We say, for example, these books are different from one another; the first one is bigger than the second.
The correct grammatical arrangement would be 'I am better than them'. If you want a comparison of the two words and their spelling, consider this sentence. 'If I win THEN I will have resounding proof I am better THAN them' 'Then' is used to show a specific time or situation (in this case after your resounding victory) and 'than' is used to compare you vs them (you will be better).
The word "accidentally" is a better than "on accident." I don't believe that on accident is grammatically correct. I am not sure what you mean by when to use it.