When you can say they are for 'they're', you always spell it this way. Follow the link to find out when to use the other ways of spelling the word pronounced this way.

Risen is the past participle of the irregular verb rise. Follow the link below to find out more and to listen to some examples.

Grown is the past participle of the irregular verb grow. Follow the link below to find out more and to listen to some examples.

Notice the two ways 'its' is spelled. Follow the link to find out why.