Question

충치이기 때문에 많이 아파요 It is important to understand the difference in the meanings of expressions 'noun 때문에' and 'noun이기 때문에'. In the first case, something expressed by the noun is the reason ('because of [noun]'). In the second case, the being of something in the state described by the noun is the reason ('because he/she/it is [noun]'). The difference can be easily understood from examples.Grammatical principles with 때문에 tend to be used more in writing and formal conversations rather than in casual speech.The clause marked by (-기) 때문에 cannot be followed by an imperative or propositive clause. -(으)니까 should be used in such cases.Unlike the similar principle -아/어서, 때문에 cannot be used in expressions of thanks and apology.

Accepted Answer

It hurts a lot because it's a cavity

Front	충치이기 때문에 많이 아파요
Back	It hurts a lot because it's a cavity
Notes	It is important to understand the difference in the meanings of expressions 'noun 때문에' and 'noun이기 때문에'. In the first case, something expressed by the noun is the reason ('because of [noun]'). In the second case, the being of something in the state described by the noun is the reason ('because he/she/it is [noun]'). The difference can be easily understood from examples. Grammatical principles with 때문에 tend to be used more in writing and formal conversations rather than in casual speech. The clause marked by (-기) 때문에 cannot be followed by an imperative or propositive clause. -(으)니까 should be used in such cases. Unlike the similar principle -아/어서, 때문에 cannot be used in expressions of thanks and apology.

때문에 Difference Expressions Case Noun Reason 충치이기 많이