"I am a traveller," he said, "I was not far from here. I couldn't go so near the castle of such a noble gentleman without meeting him."
The Giant heard this message and agreed to see the visitor. He was going to have dinner, so he was in a good mood.
"Please sit down and have dinner with me," he said to the Cat.
"Thank you, sir," said the Cat. "But first I hope you can answer a question. They say that you can change yourself into any animal. A lion, for example, or an elephant."
"That's true," said the Giant. "And I can prove it just now. Look! Whom do you see now?"
And the Giant changed himself into a big lion.
The Cat was terribly frightened. He even climbed up the curtain. Of course, it wasn't easy to climb in boots. But the lion was so big! How can you be brave and keep still near such an awful animal?
A few moments later the lion changed back into the Giant. The Cat came down.
"I'm so sorry, sir. I was very frightened," he said. "But do you know what I think? It was easy for such a big gentleman as you to change yourself into a large animal. But I'm afraid even you can't become a small animal, such as a rat or a mouse. It's just impossible."
"Impossible!" cried the Giant, very angry. "See how it's impossible!"
At the same moment he changed himself into a mouse. The mouse began to run about the floor.
It was part of the Cat's plan. He jumped on the mouse at once and ate it. So that was the end to the Giant.
the ground floor — первый этаж (the ground floor — дословно этаж на земле; так называют нижний этаж в Великобритании; the first floor — это наш второй этаж, и т. д.; в Америке этажи, как правило, называются так же, как и у нас).
a lot = much.
The Cat put on a brave face and went to the castle with his boots on. — Кот сделал вид, что ему не страшно, и, не снимая сапог, отправился в замок.
I couldn't go so near the castle of such a noble gentleman without meeting him. — Я не мог пройти мимо замка такого благородного господина, не встретившись с ним.
in a good mood — в хорошем настроении.
They say — Говорят.
change yourself into — превращаться в (Обратите внимание на то, что местоимение должно употребляться в том же числе и лице, что и подлежащее: you — yourself, he — himself.)
That's true — Всё верно.
keep still — не шевелиться, не двигаться.
ate — форма прошедшего времени глагола eat.
