Polar questions refer to questions that require a “yes” or “no” response (or equivalent synonyms in languages that do not necessarily use these words). This parameter considers the marking of polar questions, or, grammatical strategies used to distinguish polar questions from their declarative equivalents. As example data, only neutral questions should be considered; neutral questions ask whether a neutral statement is or is not true, without any implication of the expected answer. Similarly, only simple (independent-clause) questions should be considered.
NoPq: Declarative sentences and polar questions cannot be distinguished independently from pragmatic and contextual cues.
Q: Polar questions are marked by a question particle, a non-inflectional morpheme that functions specifically to mark this function and that displays a degree of independence (as an affix, clitic, or independent word). Changes in word order are of no significance for the purposes of this parameter.
QV: Polar questions are marked by the use of an auxiliary verb with an interrogative function (question verb). Changes in word order are of no significance for the purposes of this parameter.
Vq: Polar questions are marked by the use of question-specific verbal inflection (affixes or other inflectional strategies).
VWO: Polar questions are exclusively marked by movement of the verb or auxiliary, compared to the word order of the equivalent declarative sentence.
Q=or: Polar questions are marked by the coordination, through the use of a question conjunction meaning ‘or,’ of an affirmative sentence and its negative equivalent.
NoDcl: Polar questions are marked by the lack of a declarative morpheme.
PhonInt: Polar questions appear in the same word order as their declarative equivalents and are marked exclusively by intonation.
PhonNonInt: Polar questions appear in the same word order as the equivalent declarative sentences and are marked exclusively by a phonetic strategy other than intonation.
+SpecInt: Polar questions are also marked by intonation.
+SpecNonInt: Polar questions are also marked phonetically, through a strategy other than intonation.
When a language displays more than one strategy, two values can be listed. If one strategy is dominant, a slash (/) can separate the values, with the dominant value appearing first; if neither is dominant, they are listed with an ampersand (&) separating them. The use of parentheses indicates that the strategy is not obligatory, while the use of a plus sign (+) instead of an ampersand indicates that the two strategies must be used simultaneously. If simultaneous use of the two strategies is optional, an ampersand may be used, but it should be specified in the commentary whether the two strategies listed with an ampersand can optionally occur simultaneously or whether their application is restricted to one strategy at a time, along with a description of the grammatical context determining their use.
 In a neutral declarative statement, the subject (or agent) of the sentence should be the topic, while the verb and any other arguments or adjuncts constitute the comment.
 Questions that imply a specific answer, such as the tag questions “Right?” often show a different structure than neutral questions.
 In many languages, dependent questions are formed differently than independent questions. This parameter deals only with independent questions.
 Clitics are characterized by their ability to attach to lexically and syntactically distinct units, including entire phrases.
 In all known examples of this type, the verb or auxiliary moves to the front of the sentence. Word order distinctions accompanying the use of a question particle, even if obligatory, should not be labeled with this value. (See the parameter value Q.)
 For example, consider the following structure: Did you read this book (or) did you not (read this book)? Since this structure exists as an optional means of expressing polar questions in nearly every language, it need not be listed as a secondary parameter value for languages displaying a different dominant strategy. This value should only be applied if the given language uses this strategy either exclusively or as its dominant strategy.
 In some languages, statements, rather than questions, are marked. In such cases, the lack of declarative marking is used to indicate that a sentence is a question.
 For a language to qualify as this type, intonation must be the exclusive strategy used to mark polar questions. Special intonation may appear along with other question-marking strategies, but such languages will not be classified under this parameter value.