I am pre-processing some texts and I wonder what the best practice is when preparing your texts for word alignment. I don't know how aligners such as fast align and GIZA++ work under the hood, but I could assume that they take capital letters as distinguished characters. Is there, therefore, any reason to lower case your text in such a situation? Is this language dependent? It might, for instance, be interesting for a language with many capital letters, such as German, to do so or not.