The imperfect tense is used to describe an action in the past that took place over a period of time such as "I was going" or "It was sunny". It is one of the simpler Spanish verbs to conjugate with only two different sets of endings and only a few irregulars. To form it you remove the last two letters of the infinitive and add the verb endings. For -ar verbs, the endings are -aba, -abas, -aba, -ábamos, -abaís, -aban. For -er/ir verbs, the endings are -ía, -ías, -ía, -íamos, -íais, -ían. For example, to say she was playing you would take the infinitive "jugar", remove -ar and add the singular 3rd person ending to get 'jugaba'.The three irregulars are ser (which becomes, era, eras, era, éramos, eras, eran), ir (which becomes iba, ibas, iba, íbamos, ibais, iban) and ver (which becomes (veía, veías, veía, veíamos, veíais, veían).