Every verb has many tenses, and (based on Latin origin) they include present, perfect, imperfect, pluperfect, future perfect, and future. Apart from a few oddities, verbs can be changed into the perfect tense by simply removing the last letter if it is a vowel, and adding -ed to the end.
N.B. For question one there seemed to be an irregularity in grammar, hence the <u>(had)</u>. There additionally seemed to be a problem with the last half, as if the question should have been in the present tense.
Hope it helps :) and let me know if you want me to elaborate.
The repetition in the first two lines is showing a rhyme. Usually, poems are supposed to rhyme, and certain words help the poem rhyme better. In conclusion, the answer is:
