I am able to come on Saturday and help you to clean up the beach.
I can come on Saturday and help you to clean up the beach.
It's possible that many of the animals will disappear in the near future.
Many of the animals may/might/could disappear in the near future.
It isn't necessary for you to be rich to care for the environment.
You don't have to be rich to care for the environment.
It's out duty to make sure that all animals have food and shelter.
We must make sure that all animals have food and shelter.
People aren't allowed to cut down the trees in that forest.
People mustn't cut down the trees in that forest.
The rule is to have a special license to fish in that area.
You have to have a special license to fish in that area.
It's good for you to try not to waste energy to protect the environment.
You should try not to waste energy to protect the environment.
The weather is unpredictable these days. I think it's because of the climate change.
The weather is unpredictable these days. It must be because of the climate change.
The organisation uses all its money for sick animals. I am sure it doesn't make any profit.
The organisation uses all its money for sick animals. It can't make any profit.
It is important to recycle your rubbish.
You should recycle your rubbish.
