CONJUNCTION - but

Suppose that the two sentences to be joined are contrasted like this -

1. I was late. My father did not punish me.

I was late but my father did not punish me.

2. Nupur ran fast. She missed the bus.

Nupur ran fast but she missed the bus.

3. I helped Nisha. She deceived me.

I helped Nisha but she deceived me.

4. I can give you my mobile. I cannot give you my laptop.

I can give you my mobile but I cannot give you my laptop.

5. Sarthak studied hard. He failed in two subjects.

Sarthak studied hard but he failed in two subjects.