So I am trying to determine what kind of subjunctive is being used in "if...then" utterences such as: "If you are hungry, eat something." "If you are tired, go to sleep." etc.
These phrases seem to have an unspoken "should" as in: "If you are hungry then you should eat something." and "If you are happy and you know it, then you should clap your hands."
Would this be zero conditional because first conditional seems like it would be: "If you are tired, you shall go to sleep." Second Conditional would be: "If you were happy and you knew it, you should (?) clap your hands." And Third Conditional would be: "If you had been happy and you had known it, then you should have clapped your hands."
Thoughts? Is "should" somehow different in this situation than if it were "will/would have/would"?