Three past tenses

The story 'The Unlikely Best Friends' tells us what happened before, so it uses verbs in the past tense. On page 48 your book, Poorvi, shows three kinds of past tense.

The simple Past tells us that an action happened earlier. It uses the second form of the verb, often made by adding -d or -ed: looked, noticed, asked. Some verbs change in their own way: give becomes gave, go becomes went, throw becomes threw, feel becomes felt.

The Past Progressive tells us that an action was going on; it had not finished. It is made with was or were + verb + ing. With I, he, she and it we use 'was': the dog was munching, Gajaraj was missing his friend. With we, you and they we use 'were': they were playing.

The past perfect tells us that an action was already complete before something else happened. It is made with had + the third form of the verb: the king had ordered, the farmer had tied, the mahout had followed.

Here is the book's passage, with the right forms: the farmer came back and noticed that Buntee was sad. He had tied Buntee with a rope the day before (that happened first, so it is past perfect). He asked Buntee why he was sad.