1. A language learning method, comprising: transforming a first input voice from a voice receiver into an input sentence according to a grammar rule; determining whether the input sentence is the same as a learning sentence displayed on a display; and when the input sentence is different from the learning sentence, generating an ancillary information comprising at least one error word in the input sentence that is different from the learning sentence, wherein the step of transforming the first input voice from the voice receiver into the input sentence according to the grammar rule comprises: obtaining, based on the first input voice, a first phoneme sequence, wherein the first phoneme sequence represents a pronunciation of the entire first input voice; and obtaining, based on the entire first phoneme sequence, the input sentence according to the grammar rule, wherein the step of determining whether the input sentence is the same as the learning sentence displayed on the display comprises: obtaining, based on the input sentence, a second phoneme sequence, wherein the second phoneme sequence represents a pronunciation of the entire input sentence; determining whether the second phoneme sequence is the same as a standard phoneme sequence corresponding to the learning sentence; and determining whether the input sentence is different from the learning sentence when the second phoneme sequence is different from the standard phoneme sequence, wherein the step of generating the ancillary information comprising the at least one error word in the input sentence that is different from the learning sentence comprises: dividing the input sentence into at least one phrase according to a grammar format of the learning sentence; and generating the ancillary information in unit of the at least one phrase, wherein the ancillary information comprises the at least one error word and at least one phoneme of a standard phoneme sequence corresponding to the learning sentence, wherein the at least one phoneme is pronounced incorrectly and corresponded to the at least one error word, wherein the learning sentence comprises a plurality of words, and the standard phoneme sequence compliant with a grammatical structure of the learning sentence is determined according to positions of the plurality of words in the learning sentence, wherein the ancillary information further comprises a suggestion indicating to practice a pronunciation of at least two adjacent words of a specific phrase which conforms to a specific phrase structure recorded in a grammar database, wherein the at least two adjacent words comprises one of the at least one error word.