How do I form the past tense of the verb 'to go' (aller)?

The past tense, or passé composé, of the verb to go is formed using the conjugated form of the verb 'to be' - être (known as the auxiliary verb) - with the past participle, for ''aller' this is 'allé(e)'. The extra 'e' is only needed if the subject is feminine.
Most verbs in the passé composé take the verb 'avoir' as the auxiliary verb. Aller is one of the 14 verbs of motion to take être, along with: naître/mourir, aller/venir, monter/descendre, arriver/partir, entrer/sortir,apparaître, rester, retourner, tomber and e.g. their derivative forms: revenir, rentrer, remonter, redescendre, repartir.