used to connect words or ideas that are added together
I like apples and oranges, and I eat them every day.
used to show that one action follows another
She opened the door and walked in, and then she sat down.
used to show purpose or intention
Please go and buy some milk, and bring it back quickly.
used to introduce a question or comment
He said he was tired, and I asked why, and he explained.
used to show a result or consequence
Study hard and you will pass, and that will make you happy.
used in addition or mathematics
Two and three make five, and five and five make ten.
used between repeated words to show something continues or increases
The weather got hotter and hotter, and we needed more water and shade.
used between repeated words to show there are differences
There are friends and friends, and some are better than others, and we should choose carefully.