美国语言哲学家保尔·格赖斯认为, 自然语言有自己的逻辑。在会话中, 说话人和听话人首先必须愿意合作。同时, 他还提出了会话原则。
 
　　在合作原则下, 人们在交际中要遵守如下四个准则：数量准则、质量准则、关联准则和方式准则。
 
　　一、数量准则（The Maxim of Quantity）
 
　　数量准则：使自己所说的话达到当前交谈目的所要求的详尽程度, 但也不能使自己所说的话比所要求的更详尽。证券行情报道开门见山, 直截了当, 所报道的内容翔实, 没有一个多余的词。举例如下。
 
　　The Dow Jones industrial average, which on Tuesday eclipsed its old high from May 2015, gained another 0.1%, or 24 points, to finish at a new closing high of 18372.12. Finishing basically flat was the S&P500, butitstiny0.01%gain was good enough for a new closing milestone of 2152.43.（Adam Shell, 2016）（周二, 道·琼斯工业平均指数创下了自2015年5月以来的新高, 又上涨了24点, 涨幅0.1%, 以历史新高18372.12点收盘。标准普尔500指数基本以平盘报收, 但微涨0.01%, 这足以使其以新的历史最高点2152.43收盘。）这一段虽然篇幅不长, 但涵盖了所有的必要信息, 仅用两句话就把美国股市的情况报道清楚了。报道细致入微, 但无赘言。小数点都非常精确, 如：以历史新高18372.12点收盘。句子也很紧凑, 第一句相当于四个句子, 即：周二道·琼斯工业平均指数创下了自2015年5月以来的新高, 周二道·琼斯工业平均指数上涨24点, 周二道·琼斯工业平均指数上涨0.01%, 周二道·琼斯工业平均指数以历史新高18372.12点收盘。而此报道用“which”引导一个定语从句, 用连词“or”的短语, 再用不定式短语“to finish...”, 把句子灵活地连成一个井然有序的句子。第二句也相当四个句子, 即：标准普尔收盘, 标准普尔涨幅, 标准普尔涨幅尽管很小但足够好, 标准普尔创历史新高收盘。文中用现在分词短语“finishing...”、转折连词“but”、介词短语“for”将它们巧妙地结合成一个句子。
 
　　二、质量准则（The Maxim of Quality）
 
　　质量准则：不要说自己认为不真实的话, 不要说自己缺乏足够证据的话。为了使证券行情报道更真实形象, 如同行情就在投资者眼前进行一样, 证券行情报道使用现在时, 即一般现在时、现在进行时, 对现在有影响的现在完成时。举例如下。
 
　　Stocks That feast During Thanksgiving WeekThe Thanksgiving week often is a bullish feast for stock investors, with the S&P500 stock index posting average returns of 0.63% the past 50 years, above the punier 0.14% gain in all weeks, according to Schaeffer's Investment Research.
 
　　Investors looking to profit from the positive vibes of what's left of the holiday-shortened Thanksgiving week should keep their money in the stock market.
 
　　U.S. stocks have posted average gains of 0.33% on the Wednesday before turkey day, closing positive 82% of the time. Similarly, the S&P500 has gained 0.27% on average on the Friday after Thanksgiving, finishing up 70% of the time. (One caveat: Stock shave finished down the Friday after Thanksgiving five of the past six years, Schaeffer's Investment Research says.
 
　　But investors looking to really cash in during the Thanksgiving week should consider stocks that have fared the best the past 10 years. The best-performing stock over the last decade in the four-session trading week is upscale fashion retailer Nordstrom, which has posted average returns of 6.4%. This year the retailer is living up to its reputation, gaining 4.6% through Tuesday. Coach, the high-end maker of leather goods and hand bags, also is a solid pick, gaining 5.5% on average since 2005 and rallying more than5% this week. Other winners: high-end jewelry maker Tiffany and iPhone maker Apple. So far this week, Tiffany shares are moving higher, but Apple shares have dipped（Adam Shell, 2015）这篇证券行情的报道一共使用了十四个谓语动词，其中六个是一般现在时，六个现在完成时，两个现在进行时。
 
　　证券行情报道的标题通常情况下使用一般现在时。
 
　　为了证实说的是真话，没有虚假掩饰，证券行情报道都用原话，也就是使用直接引语。直接引语是新闻的重要组成部分，是对事件的直接描述，真实、有感情，能让读者感受到现场的气氛。此外，还可以增强新闻的人情味、感染力。言为心声，在新闻中，直接引语最能传达出说话者的心情感受，感染读者。新闻中人物怎样说的，说了什么，有无隐含意思，恰当的直接引语完全能够表达出来，包括说话者的情感心态，即使这种情感比较复杂。