Inshallah means "God willing" or "If God wills it."
After teaching here for a bit now here is how a conversation between a student and myself normally goes...
Me "Okay so you are going to do your spelling homework tonight, right"
Student "Miss. Catie, Inshallah I will do my homework!"
Then the next day my student will come in and he has not done his homework. I guess God did not will him to do it that night!