In Brazilian Portuguese when does one use the "sh" at end or "s" sound?

Depois sounds like de-poy-sh, but ingles sounds like een-glays with no "sh" sound at the end after the vowel, is there a commom rule for when to add the "sh" sound when a vowel is before it? Also, when does one know when to make de and te or di and ti "chee" sounds at the end?