A suspended sentence is a legal term that means that the court has found your boyfriend guilty of whatever crime was committed, but he does not have to serve an jail time. For example, if the judge gave your boyfriend a 18-month suspended sentence, your boyfriend will be put on probation for 18 months instead of serving in jail.
Suspended imposition means if he follows the order he won't be sentenced. Suspended execution means the court sentenced him if he follows the order he won't serve time.
After a conviction in a criminal trial and a fine or penalty is ordered by the court, the judge may suspend the sentence. The effect of the suspended sentence is that even though the sentence has been imposed, it will not be enforced.
After proceeding through the criminal justice system, a defendant ultimately is sentenced by the judge. The judge may then suspend the sentence, thus making it null and void.