"There is, in this regard, a pertinent story about the great American linguist and anthropologist Edward Sapir, who had allegedly been working with an informant on an American Indian language with a grammar that he was having trouble sorting out. Finally, he felt he had caught on to the principles involved, and to test his hypothesis he began making up sentences in the language himself. "Can you say this?" he would ask his informant and would then produce his utterance in the informant's language. He repeated this several times, each time composing a different expression. Each time his informant nodded his head and said "Yes, you can say that." This apparently was a confirmation that he was on the right track. Then an awful suspicion crossed Sapir's mind. Once more he asked "Can you say this?" and once more received the answer "Yes." Then he asked, "What does it mean?" "Not a darn thing!" came the reply.
Ward H. Goodenough, "Culture, Language, and Society"
It is possible to speak or write perfectly acceptable things that do not mean anything. :-D