From Longman Dictionary of Contemporary Englishbecausebe‧cause1 /bɪˈkɒz, bɪˈkəz $ bɪˈkɒːz, bɪˈkəz/ ●●●S1W1 conjunction 🔊 🔊 1BECAUSEused when you are giving the reason for something 🔊 We didn’t enjoy the day because the weather was so awful. 🔊 ‘Why can’t I go?’ ‘Because you’re not old enough.’ 🔊 Hubert never experienced any fear, and this was partly because he was not particularly intelligent. 🔊 Many exam candidates lose marks simply because they do not read the questions properly. 🔊 I decided to go with them, mainly because I had nothing better to do.2 →just because ...GRAMMAR: Comparisonbecause • You use because at the beginning of a clause, when giving the reason for something: I was late because the traffic was bad.• In formal written English, don’t use because at the beginning of a sentence.because of• You use because of before a noun, when giving the reason for something: I was late because of the traffic.✗Don’t say: because the trafficTHESAURUSbecause conjunction used when giving the reason for somethingI went home because I was tired.The streets were flooded because of all the rain.due to/owing to preposition used to give the reason why something has happened. Due to and owing to are more formal than becauseThe delay was due to a problem with the ship’s engines.The parade had to be cancelled owing to bad weather.through preposition because of something. Through is used especially when saying why someone succeeded or failed to do somethingThey won the game, more through luck than skill.You failed that test through carelessness.thanks to preposition used when explaining that something good has happened because of someone’s efforts, or because something existsThanks to modern medicine, the disease can now be cured.since/as conjunction used when giving the reason why someone decides to do something or decides that something is trueWe decided to go to the beach since it was a nice day.I thought Kevin was out as his car wasn’t there.out of preposition because of a particular feeling or qualityHe started reading the book out of curiosity.I only asked out of politeness.