so, but, because, and

 Connectives

And, but, so, because, therefore, however

And: links two related things

Ex: I like tea and coffee.

But: links a positive (+) and negative (-) idea.

Ex: I like swimming but I don't like dancing.

so: gives a result

Ex: I was hungry, so I ate my lunch.

Because: gives a reason

Ex: I ate my lunch because I was hungry

or: give an option, choice

Ex: Do you want Vietnamese tea or milk tea?

therefore:

Ex: Hoa failed her math test. Therefore, she has to do the test again.

However: 

Ex: Na is very tired. However, she has to finish her homework before she goes to bed.