Should or Ought to

The verbs should and ought to are mainly used for giving advice.

Many students do not like ought to because it looks strange and sounds strange.  This is fine because, as you will see from the diagram below, it is not necessary to use ought to if you do not want to.  However, native speakers use this quite a lot, so for more advanced speakers here is a simple diagram of when to use should and when it is possible to use ought to.