Linguistic.swift

import Foundation

struct Linguistic {

    typealias LinguisticTag = (token: String, tag: String)
    
    static func tags(text: String, range: NSRange? = nil, language: String = "en") -> [LinguisticTag] {
        let options: NSLinguisticTaggerOptions = [.OmitWhitespace, .OmitPunctuation, .JoinNames]
        let schemes = NSLinguisticTagger.availableTagSchemesForLanguage(language)
        let tagger = NSLinguisticTagger(tagSchemes: schemes, options: Int(options.rawValue))
        tagger.string = text
        
        let range = range ?? NSRange(location: 0, length: text.characters.count)
        let scheme = NSLinguisticTagSchemeNameTypeOrLexicalClass
        var tags = [LinguisticTag]()
        
        tagger.enumerateTagsInRange(range, scheme: scheme, options: options) { tag, tokenRange, _, _ in
            let token = text.substringWithRange(tokenRange)
            tags.append(LinguisticTag(token: token, tag: tag))
        }

        return tags
    }
    
}

private extension String {
    
    func substringWithRange(range: NSRange) -> String {
        return string.substringWithRange(range)
    }
    
    func linguisticTagsInRange(range: NSRange, scheme tagScheme: String, options opts: NSLinguisticTaggerOptions) -> [String] {
        return string.linguisticTagsInRange(range, scheme: tagScheme, options: opts, orthography: nil, tokenRanges: nil)
    }
    
    private var string: NSString {
        return self as NSString
    }
    
}

LinguisticExample.swift

Linguistic.tags("Mary Jane, please, could you tell me if that bus is going to Los Angeles or to San Francisco?")
// [("Mary Jane", "PersonalName"), ("please", "Interjection"), 
// ("could", "Verb"), ("you", "Pronoun"), 
// ("tell", "Verb"), ("me", "Pronoun"), 
// ("if", "Preposition"), ("that", "Determiner"), 
// ("bus", "Noun"), ("is", "Verb"), ("going", "Verb"), 
// ("to", "Preposition"), ("Los Angeles", "PlaceName"), 
// ("or", "Conjunction"), ("to", "Preposition"), ("San Francisco", "PlaceName")]

Linguistic.tags("What is the weather like today in San Francisco?")
// [("What", "Pronoun"), ("is", "Verb"), ("the", "Determiner"), ("weather", "Noun"), ("like", "Preposition"), ("today", "Noun"), ("in", "Preposition"), ("San Francisco", "PlaceName")]

Linguistic.tags("What is the weather in San Francisco?", range: NSRange(location: 5, length: 2))
// [("is": "Verb")]

LinguisticExamplePlaces.swift

// Places names

let tags = Linguistic.tags("Mary Jane, please, could you tell me if that bus is going to Los Angeles or to San Francisco?")
let places = tags.filter { $0.tag == "PlaceName" }.map { $0.token }
// ["Los Angeles", "San Francisco"]