Difference between should and ought to - Should and ought difference

first let's look at should and ought these two  verbs are very similar and can often replace  

each other this means most of the time if i use  the word should i can also just replace it with  

the word aut or octu although in english should is  used much more often than ought so if the word art  

confuses you or you don't use it very often  that's okay you can use should in place of it  

so let's take a look at some examples of how we  can use should and ought to interchangeably or  

some examples that show that we can use these  words in just the same way first example  

you should see star wars it's a great series or  you ought to see star wars it's a great series  

so here i'm telling you i think it's a good  idea for you to see star wars i think you should  

do it i think you ought to do it same meaning  here's another example you should join us you  

ought to join us so here i'm suggesting or  saying that it's a good idea come on come on  

you should join us you ought to join us so we can  see in these two examples that we can use should  

and ought to in very much the same way let's  look at another way should and ought can be used  

should and ought are also used to talk about  logical probability what is logical probability  

this means something that is most likely true  if i think about it it's probably true so let's  

take a look at an example i bought two pizzas that  should be enough i bought two pizzas that ought to  

be enough so let's say i'm having some friends  over and i decide to order some pizzas i think  

most definitely right really most probably that  two pizzas will be enough for all of my friends  

so i could say that should be enough or that ought  to be enough not quite the same as saying that is  

enough uh maybe right there's a tiny tiny chance  maybe we'll eat two pizzas and we still want more  

but i look around and i think hmm that should be  enough that ought to be enough let's see another  

example uh let's say i am waiting for my friend  jack to come over and finally i hear a knock on  

the door oh that should be jack knocking on the  door or that ought to be jack knocking on the door  

so i was expecting him if someone comes and knocks  on my door it is most likely most probably jack  

right i'm expecting him there's a small chance  that maybe maybe it's the the post man uh or maybe  

it's someone else but most probably it's jack ah  that ought to be jack so here we see we can use  

should and ought to talk about logical probability  or something that is most most most likely true