# Grammatical-Analysis Details These constants are used as the keys in the outDetails dictionaries returned by [`NSSpellServer`](/documentation/Foundation/NSSpellServer) and (). ## Topics ### Constants [`let NSGrammarRange: String`](/documentation/Foundation/NSGrammarRange) The value for the `NSGrammarRange` dictionary key should be an `NSValue` containing an `NSRange`, a subrange of the sentence range used as the return value, whose location should be an offset from the beginning of the sentence–so, for example, an `NSGrammarRange` for the first four characters of the overall sentence range should be `{0, 4}`. If the `NSGrammarRange` key is not present in the dictionary it is assumed to be equal to the overall sentence range. [`let NSGrammarUserDescription: String`](/documentation/Foundation/NSGrammarUserDescription) The value for the `NSGrammarUserDescription` dictionary key should be an `NSString` containing descriptive text about that range, to be presented directly to the user; it is intended that the user description should provide enough information to allow the user to correct the problem. It is recommended that `NSGrammarUserDescription` be supplied in all cases, however, `NSGrammarUserDescription` or `NSGrammarCorrections` must be supplied in order for correction guidance to be presented to the user. [`let NSGrammarCorrections: String`](/documentation/Foundation/NSGrammarCorrections) The value for the `NSGrammarCorrections` key should be an `NSArray` of `NSStrings` representing potential substitutions to correct the problem, but it is expected that this may not be available in all cases. `NSGrammarUserDescription` or `NSGrammarCorrections` must be supplied in order for correction guidance to be presented to the user. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)