The past tense is a grammatical tense whose function is to place an action or situation in the past. Examples of verbs in the past tense include the English verbs sang, went and washed. Most languages have a past tense, with some having several types in order to indicate how far back the action took place. Some languages have a compound past tense which uses auxiliary verbs as well as an imperfect tense which expresses continuous or repetitive events or actions. Some languages inflect the verb, which changes the ending to indicate the past tense, while non-inflected languages may use other words meaning, for example, "yesterday" or "last week" to indicate that something took place in the past.