Sometimes natural language, rather than a diagram, feels like the most natural way to describe some concept. However, our formal systems cannot disambiguate natural language descriptions unless they are supplied in a highly structured way. For this reason, many of our systems use natural language only at points in the interaction where there is a fixed set of choices of formal expression, which allows the system to generate natural language paraphrases of the formal expressions and present these as menus of choices to the designer. This means that the designer has responsibility only for recognising appropriate natural language expressions, not for inventing them. In Section 5.2 a menu based interface is used to assist ecological modellers in providing a problem description. In Section 7.2 we use menus of natural language statements to allow reserve selectors to choose selection strategies.