Write negative sentences. Use the short forms of the verb to be. 1) She's eleven. She's in the classroom. She isn't eleven. She ______. 2)They're happy. They're in the house. They______ . 3) He's a teacher. He's ready for school. He______ . ____. He_______. ________.

She isn't eleven. She is twelve.
В этой фразе мы меняем возраст с одиннадцати лет на двенадцать, создавая отрицательное предложение с краткой формой глагола "to be" (isn't).

They aren't happy. They are sad.
Здесь мы меняем эмоциональное состояние, используя отрицательную форму "aren't" (от "are not"). Вместо "happy" мы ставим "sad".

He isn't a teacher. He is a student. He isn't ready for school. He is tired.
В этой последовательности фраз сначала мы меняем профессии: "isn't a teacher" вместо "is a teacher". Затем, во второй части, выражаем его состояние, утверждая, что он "is tired" (устал), а не "ready for school" (готов к школе).