As we saw in the preceding chapter, the problem of analysis comprises two major components: the knowledge available to the learner and the input on which the analysis is to be performed. In the synthesis problem, there is a counterpart to the first component, but there is no component comparable to the input in analysis, unless it be the speaker's ‘communicative intention’. In a sense, this communicative intention is the raw material on which the speaker has to work with all his available knowledge in order to produce an utterance which he considers understandable and appropriate in a given context. But the analogy is obviously rather fuzzy: the speaker cannot learn from his communicative intention in the same way as he can indeed learn from the input with its various structural properties. The essential component is therefore the learner's available knowledge, particularly but not exclusively his knowledge of the target language, acquired through earlier input analyses (we know that such knowledge varies in reliability, from solid facts to vague suppositions or even to false assumptions). Before attempting to synthesize an utterance, the speaker must have at his disposal some elementary entities that can be put together. This is not to say that he must be fairly advanced in his analysis when starting a synthesis: he may try to form some utterances on the basis of a rather limited repertoire, which do not conform at all to the standards of the target language.