「語用互文」涉及先後兩個文本之間的關聯觸發及互動，由後發生的「後像文本」（例如：「吃比瘦有福」）中之言詞或概念直接引用或間接影射先發生的「來源文本」（例如：「施比受有福」），使接收者得以察覺或推論其回應指涉。筆者考察《聯合報》與《紐約時報》新聞標題各1,500則，辨認並分析其中之語用互文，期能比較語用互文之出現頻率、了解其來源文本及言談共知（common ground）、闡釋其社會文化意涵。結果發現兩家報紙標題中語用互文出現頻率差異不大，但《紐約時報》標題之互文密度較高。來源文本代表語用互文的言談共知，也反映互文關聯的文化樣態。《紐約時報》標題互文隱含較多的熟語、媒體產品、文學作品、非文學著作的知識及文化思維；《聯合報》標題互文呈現較廣泛的一般詞語（非熟語）之挪用或翻轉，此一對照顯示出兩家報紙標題書寫與閱讀之歷時性語文知識樣態之差異。高達半數之《聯合報》標題互文為一般詞語原意之轉變（雙關或隱喻），遠多於《紐約時報》標題互文一般詞語原意之轉變。這類互文之來源（一般詞語）較易於引動，但陌生化的創新或巧思往往較少。此外，《聯合報》標題之雙關互文多為諧音的形式關聯，而《紐約時報》標題之雙關互文多為同音字詞兼指兩種意義之形式及概念運作。
A pragmatic intertext (PI) involves the activation and interaction of two texts, with the later 'alluding text' (e.g., 'Home Smart Home') quoting or reflecting the earlier 'source text' (e.g., 'Home, Sweet Home') in such a way that the recipient can perceive or infer the intertextual reference. This article analyzes PIs drawn from 1,500 New York Times (NYT) and 1,500 United Daily News (UDN) news headlines to shed light on their occurrence frequencies, source texts, common grounds, and sociocultural implications. It is found that the PI occurrence frequencies are quite close, but the PI density of the NYT headlines is higher than that of the UDN ones. The source text represents the intertextual common ground and reflects the cultural modality of the intertextual association. The NYT headlines contain much more PIs derived from the cultural modalities of formulaic expressions, non-print media products, literary works, and non-literary works. On the other hand, the UDN headlines demonstrate much more extensive use of deviated general expressions. This contrast gives an overview of the paradigmatic linguistic and cultural knowledge underlying the writing and reading of the PIs in the two groups of headlines. In addition, as many as half of the UDN PIs are punning or metaphorical ones with a general expression as their source text, much more than their counterparts in the NYT headlines. PIs of this type are easier to evoke, albeit with less de-familiarized ingenuity. Most UDN punning PIs are homonymic, while most NYT punning PIs are both homonymic and polysemic.