Question about preposition with the word 'tough'
Hi. while I was looking up the word tough in Oxford Learners Dictionary, I saw something that makes me difficult to understand how to use this word with a preposition.

Here is an example:
tough (on somebody/something) Don't be too tough on him—he was only trying to help.
tough (with somebody/something) It's about time teachers started to get tough with bullies.

In these sentences, can I replace "tough on" to "tough with"?
And could you give me some advice about how to learn or understand prepositions?

Thank you.

Question

Question about preposition with the word 'tough'
Hi. while I was looking up the word tough in Oxford Learners Dictionary, I saw something that makes me difficult to understand how to use this word with a preposition.

Here is an example:
tough (on somebody/something) Don't be too tough on him—he was only trying to help.
tough (with somebody/something) It's about time teachers started to get tough with bullies.

In these sentences, can I replace "tough on" to "tough with"?
And could you give me some advice about how to learn or understand prepositions?

Thank you.

Answer

be tough on 
get tough with

In colloquial American, "be tough on" usually refers to rule enforcement, or treatment within a process. "My parents aren't too tough on me when I break curfew."

"get tough with" is more general, but I think less common, meaning taking a more belligerent or confontational position with an adversary.

Both phrases are also used non-coloquially and often nonsensically to describe positions in American politics.

Answer

To be  honest, I hear the former expression more much than the latter.

-- The president enacted many tough on crime policies.
-- He was just trying to help you. You didn't have to be so tough on him.

The second one makes me think more of a specific situation. "Get tough with (someone)".

For example, a child is arguing with her mother and the mother replies by saying "Don't get tough with me".

That is my opinion as an American English speaker. There might be regional differences that I may not be aware about (:

Answer

Yes.  In your example, "tough on" and "tough with" mean essentially the same thing.

There is no easy way to know which preposition to use other than reading and listening.  In other words: practice, practice,  practice.  This is because the choice of preposition used is often arbitrary and follows no rule that can be learned.  I am not an English teacher but I am aware that they teach about "phrasal verbs" to help explain which preposition to use for different meanings.