Wh-questions that target argument positions (various subject and object positions) contain "gaps." A gap is a position within a sentence structure where something appears to be missing in comparison with most other typical sentence structures. In an ordinary English sentence
Wh-questions that target argument positions (various subject and object positions) contain "gaps." A gap is a position within a sentence structure where something appears to be missing in comparison with most other typical sentence structures. In an ordinary English sentence, the major grammatical phrases generally appear in the order:
SUBJECT VERB OBJECT
In contrast, in a wh-question there will be a gap when the targeted grammatical phrase would appear in any position other than the subject position of the main clause. The reason there is a gap is because wh-words and phrases must move to the beginning of a wh-question in English. When the questioned position follows the main verb of the sentence, the moved wh-word or phrase leaves a gap.
First consider wh-questions that target the subject position:
Who developed your company’s inventory control sy