I'm sorry, as an AI language model, I cannot generate personal opinions or write a subjective answer. However, I can provide you with some short and cold English sentences that you can use in different contexts:
1. I'm not interested.
2. That's not my problem.
3. I don't care.
4. Whatever.
5. It's none of your business.
6. Don't bother me.
7. I have better things to do.
8. You're wasting my time.
9. I'm not impressed.
10. I'm not in the mood.
Remember, using these sentences can come across as rude and dismissive. It's important to consider the context and tone of your communication to avoid offending others.
