What is the difference between "should" and "ought to"?

I don't think there's a big difference.

I find "ought to" a little more mild though. "Should" is more of an imperative, "ought to," to me, contains a slight implication that you won't, even though it would be better if you did.

I can't really think of any sentences where one or the other makes a significant difference though.

Got it.
Thank you.

I disagree, Soz. How can 'ought to' contain any implication that "you" won't, when the person receiving the advice [inherent in should/ought to] is different from the person offering the advice.

A: [to B] You ought to/should go see [movie name]. It's really good.

At this point, A has no idea how the advice will be received by B.

should/ought can both be weakened or strengthened - probably, likely definitely should/ought to ... .

Do you wanna know What the difference is in those two sentences or generally, Ori?

Of course, JTT. Please go ahead. I'm all ears.

There's no difference imo.

Oh but there is, Sire. Put your superb synapses to afirin`and you`ll see.

What did I hit on my keyboard to cause that odd apostropheÉ And the even odder question mark.

So pray enlighten us.

They are used in different registers, to be sure, but I don't discern a real difference in meaning, nor in emphasis.

Yes. Let His Excellency JTT enlighten us, directly.
Both Sire McTag and I are waiting .

Looks like he's stumped, Ori.

He's on the stump, Sire.

Should and ought have similar meanings. They can both be used to discuss obligation, or to give advice or instructions.

Obligation:

We should respect our parents.
We ought to respect our parents.

You should stop smoking.
You ought to stop smoking.

Advice:

If you want to grow healthy tomatoes, you should water them often.
If you want to grow healthy tomatoes, you ought to water them often.

Whether obligation or suggestion is being conveyed is dependent on context.

See also must.

Must is stronger than should and ought.

You must stop smoking. (A command.)
You should/ought to stop smoking. (A piece of advice.)

Must expresses certainty. Should/ought to expresses probability.

He must be home now. (It is certain.)
He should be home now. (It is probable.)