1. I was thinking of not using the distinction between "specific" and "non-specific time" as the reasoning to validate the rule, because while this distinction is correct, it is difficult to demonstrate. Which makes it less than convincing to anyone who thinks there's a conspiracy behind it!!!Originally Posted by Casiopea
2. I agree with you re the examples after adding "before": the "past time expression" becomes "parenthetic" in a sense.
(d) "I have eaten lunch (in the afternoon) before" is equivalent (grammar-wise) to "I have eaten lunch (in the presidential suite) before". With or without "before", the adverb phrase "in the afternoon" remains as such BUT in the latter case the adverb phrase is further modified by the adverb "before", and the meaning changes. :wink: