Many Natural Language Interfaces (NLIs) to knowledge bases have been developed in order to provide easy access to structured data for casual users. However, those that have reasonable performance are domain-specific and tend to require customisation for each new domain, which, from a developer’s perspective, makes them expensive to maintain and unattractive for practical applications spanning different domains. This paper explores how the performance of existing NLI systems to knowledge bases can be improved without the extra cost of extensive customisation. Additionally, usability of NLIs to knowledge bases is explored from two aspects: that of the developer who is customising the system and that of the end-user who is querying it. We discuss existing methods for increasing the usability of NLI systems and their impact on the overall retrieval performance.