Passado contínuo

Afirmativas
As frases afirmativas no past contínuous são compostas do sujeito mais o verbo TO BE no passado, seguido do gerúndio do verbo principal. Veja alguns exemplos:

- They were reading (eles estavam lendo)
- I was learning (eu estava aprendendo)

* Lembrete: tabela do verbo TO BE no passado:

I – Was
You – Were
He – Was
She – Was
It – Was
We – Were
You – Were
They – Were

Interrogações
As frases interrogativas do past continuous apenas trocam o sujeito principal com o gerúndio do verbo, como no Presente Contínuo:

- Were they reading? (Eles estavam lendo?)
- Was I learning? (Eu estava aprendendo?)

Negações
Para converter uma frase afirmativa do past continuous para negativa, basta apenas adicionar o NOT depois do verbo TO BE:

- They were not (weren’t) reading (eles não estavam lendo)
- I was not (wasn’t) learning (eu não estava aprendendo)

http://www.infoescola.com/ingles/passado-continuo-past-continuous/