Translation:I had already read the book yesterday.
Why does this translate only to the English past perfect: "I had already read the book yesterday.? Could it also be translated to the past progressive, meaning: "I was already (in the process of) reading the book yesterday."? This is closer to my understanding of the explanation in the Tips ¬es.
Never mind, I've answered my own question! It is Mi jam estis leginta (I had already read) rather than Mi jam estis leganta (I was already reading). I guess I should clean my glasses and look at every letter! ;)