Dictionary API

I require a C# .NET program running under WinForms or online to use a dictionary API to find out if a word is a verb, adverb, noun, etc. Therefore the code will look something like this: string wordType = findWordType(word); // wordType is adjective, noun, etc In cases when a word can have several types, eg Just then a DataSet would be required: DataSet wordTypes = findWordType(word); I have found one API at [login to view URL] but any adequate one is OK by me. Please pay attention to efficiencies and API limits.