yīnwèi wǒ hěn máng, suǒyǐ wǒ bù néng gēn nǐ yìqǐ qù kàn diànyǐng.

Because I am very busy, I can’t go watch a movie with you.

Breakdown of yīnwèi wǒ hěn máng, suǒyǐ wǒ bù néng gēn nǐ yìqǐ qù kàn diànyǐng.

• 我wǒ: I
• 你nǐ: you
• 不bù: not
• 很hěn: very

Questions & Answers about yīnwèi wǒ hěn máng, suǒyǐ wǒ bù néng gēn nǐ yìqǐ qù kàn diànyǐng.

Do I need both 因为 and 所以? It feels redundant compared with English.

Using both is normal and very common in Chinese.

• Full form: 因为…，所以… (Because…, therefore…)
• You can drop 所以: 因为我很忙，(所以) 不能…
• Or drop 因为 and just state the reason first: 我很忙，所以不能… Avoid using neither; at least one of them (or clear context) should mark the cause–effect relationship.

Can I drop the second 我?

Yes. If the subject doesn’t change, you can omit it in the second clause:

• 因为我很忙，所以不能跟你一起去看电影。 Keeping it (as in the original) is also fine and slightly more explicit.

Why is 很 before 忙? Does it always mean “very”?

In predicate adjective sentences, 很 often functions as a neutral linker, not necessarily “very.” 我很忙 usually just means “I’m busy.”

• Neutral description: 我很忙。
• Truly emphatic: 我非常忙 / 我真的很忙 / 我太忙了。
• 我忙 is grammatical but tends to sound contrastive/abrupt (e.g., answering 你忙不忙？— 我忙。).

Why not use 是 with the adjective (e.g., 我是很忙 / 我是忙)?