15. The non-transitory computer readable medium of claim 9 , wherein the context free grammar further comprises a second sentence that includes the elements of the formerly received natural language query, wherein in the second sentence the given keyword in the formerly received natural language query is replaced with a second label representing a second, different one of the plural different database attribute types, and wherein responding to the new natural language query by generating the database language query is further based on accessing the context free grammar that includes the first and second sentences.
15. The non-transitory computer readable medium of claim 9 , wherein the context free grammar further comprises a second sentence that includes the elements of the formerly received natural language query, wherein in the second sentence the given keyword in the formerly received natural language query is replaced with a second label representing a second, different one of the plural different database attribute types, and wherein responding to the new natural language query by generating the database language query is further based on accessing the context free grammar that includes the first and second sentences. 16. The non-transitory computer readable medium of claim 15 , wherein the instructions are for further causing the at least one processor to assign probabilities to the first and second sentences, where the probabilities correspond to likelihoods that respective ones of the first and second sentences will translate into respective expressions of the database language query that produce a correct answer to the new natural language query.