1. Data The frequency of "a lot of" varies significantly across genres, with the highest frequency found in Spoken language and the lowest in Academic writing. The construction is also more common in online and informal genres, such as Blogs and Web-General, compared to more formal genres like Newspapers and Magazines. In terms of time periods, the frequency of "a lot of" has been steadily increasing over the years, with a notable jump between 2005-2009 and 2010-2014.

2. Possible explanation The frequency differences across genres may be attributed to the level of formality and the purpose of communication. Spoken language, being more conversational and informal, tends to favor the use of "a lot of" as a convenient way to express quantity. Online genres, such as Blogs and Web-General, also exhibit a more casual tone, which may contribute to the higher frequency of this construction. In contrast, Academic writing, being more formal and precise, may opt for more nuanced and technical ways to express quantity. The increasing frequency over time may be due to the growing informality of written communication, particularly with the rise of online writing and social media.

3. Competing constructions In genres where "a lot of" is relatively infrequent, such as Academic writing, alternative constructions may be used to express quantity. For instance, more formal and precise phrases like "a significant amount of" or "a substantial number of" might be preferred. In addition, Academic writing may employ more technical vocabulary, such as "numerous" or "copious," to convey quantity. In the earlier time periods, other phrases like "a great deal of" or "a large number of" might have been used more frequently, but have since been replaced by the more conversational "a lot of."