5. sollen (to be supposed to, should/ought to)
Present: Er soll reich sein. He's supposed to be rich. / It's said that he's rich.
Past/Preterite: Er sollte gestern ankommen. He was supposed to arrive yesterday.
Pres. Perfect/Perfekt: Du hast ihn anrufen sollen. You should have called him.
Future (in sense of): Er soll das morgen haben. He'll have that tomorrow.
Subjunctive/Konjunktiv: Das hättest du nicht tun sollen. You shouldn't have done that.
Subjunctive/Konjunktiv: Wenn ich sollte... If I should...
Subjunctive/Konjunktiv: Sollte sie anrufen... If she should (happen to) call...
Sample Idiomatic Expressions:
Das Buch soll sehr gut sein. The book is said to be very good.
Du sollst damit sofort aufhören! You're to stop that right now!
Was soll das (heißen) What's that supposed to mean What's the idea
Es soll nicht wieder vorkommen. It won't happen again.