In Latin, most verbs have four principal parts. For example, the verb for "to carry" is given as "portō – portāre – portāvī – portātum", where "portō" is the first-person singular present active indicative ("I carry"), "portāre" is the present active infinitive ("to carry"), "portāvī" is the first-person singular perfect active indicative ("I carried"), and "portātum" is the neuter supine. Most of the verb forms in Latin derive from the first two principal parts: "portābō", "I shall carry", is derived from the root "portā-", taken from the present infinitive. However, all active perfect forms are derived from the third principal part (so "portāveram", "I had carried", is taken from "portāv-") while the perfect participle ("portātus, portāta, portātum", "having been carried") is derived from the supine and is used to form perfect passive participle with the auxiliary verb "sum" (such as "portātum est", "it has been carried"). The auxiliary verb is often dropped when writing poetry in Latin.