Literal translation, direct translation, or word-for-word translation is a translation of a text done by translating each word separately without looking at how the words are used together in a phrase or sentence. In translation theory, another term for literal translation is metaphrase (as opposed to paraphrase for an analogous translation). It is to be distinguished from an interpretation (done, for example, by an interpreter). Literal translation leads to mistranslation of idioms, which was once a serious problem for machine translation. The term "literal translation" often appeared in the titles of 19th-century English translations of the classical Bible and other texts. Word-for-word translations ("cribs", "ponies", or "trots") are sometimes prepared for a writer who is translating a work written in a language they do not know. For example, Robert Pinsky is reported to have used a literal translation in preparing his translation of Dante's Inferno (1994), as he does not know Italian. Similarly, Richard Pevear worked from literal translations provided by his wife, Larissa Volokhonsky, in their translations of several Russian novels. Literal translation can also denote a translation that represents the precise meaning of the original text but does not attempt to convey its style, beauty, or poetry. There is, however, a great deal of difference between a literal translation of a poetic work and a prose translation. A literal translation of poetry may be in prose rather than verse but also be error-free. Charles Singleton's 1975 translation of the Divine Comedy is regarded as a prose translation. "Literal" translation implies that it is probably full of errors, since the translator has made no effort to (or is unable to) convey correct idioms or shades of meaning, for example, but it can also be a useful way of seeing how words are used to convey meaning in the source language. A literal English translation of the German phrase "Ich habe Hunger" would be "I have hunger" in English, but this is clearly not a phrase that would generally be used in English, even though its meaning might be clear.