be·cause 
/bɪˈkɑ:z, bɪˈkʌz/ conjunction
/bɪˈkɑ:z, bɪˈkʌz/ conjunction : for the reason that
▪ I ran because I was afraid. ▪ We were late because our car wouldn't start. = Because our car wouldn't start, we were late. ▪ “Why did you do it?” “Because she told me to.”
▪ I ran because I was afraid. ▪ We were late because our car wouldn't start. = Because our car wouldn't start, we were late. ▪ “Why did you do it?” “Because she told me to.”
because of
: for the reason of
▪ The picnic has been canceled because of [=due to, on account of] bad weather. ▪ Because of this [=for this reason], only very rich people can afford to live on the island. ▪ Because of you, we missed the bus. [=you caused us to miss the bus] ▪ The accident happened because of [=through] carelessness.
▪ The picnic has been canceled because of [=due to, on account of] bad weather. ▪ Because of this [=for this reason], only very rich people can afford to live on the island. ▪ Because of you, we missed the bus. [=you caused us to miss the bus] ▪ The accident happened because of [=through] carelessness.
just because
: for the simple or single reason that
▪ Don't get nervous just because the teacher might ask you a question. ▪ We can't assume it will rain today just because it rained yesterday. ▪ Just because your friends do it, that doesn't mean that you should do it, too.
▪ Don't get nervous just because the teacher might ask you a question. ▪ We can't assume it will rain today just because it rained yesterday. ▪ Just because your friends do it, that doesn't mean that you should do it, too.
