She is explain new grammar material now - настоящем времени 4 предложения she was - в времени she will be explaining в вопросительные и отрицательные 4 предложения

She was explaining... - в времени
She will be explaining - в будущем времени.
Was she will be explaining?  Will she be explaining? - вопросительные предложения.
She was not explaining. She will not be explaining - отрицательные предложения