Lewis, Laura and Lyle all had lattes (Luna’s clue).
No one next to Laura had black coffee. Since black coffee is in every column, the only person who could have gotten it in the fifth column is George.
Since George is surrounded by people who got tea (George’s clue), and no one next to Laura got black coffee, the only people in the fourth column who could have black coffee is Art.
Since no one else is Art’s row had black coffee (Art’s clue), and no one next to Laura got black coffee, the only people in the third column who could have black coffee is Brandon.
Olivia must be some type of tea (George’s clue), but no one in Brandon’s row had chai tea (Brandon’s clue), so she must have gotten green tea. Since each column has five different drinks (Lewis’s clue), and Patrick is also some type of tea, he must be chai tea.
Renee had tea (Olivia’s clue), but no one in Brandon’s row had chai tea (Brandon’s clue), so she must have gotten green tea. Since each column has five different drinks (Lewis’s clue), May got chai tea.
Since no one else is Art’s row had black coffee (Art’s clue), and each column has someone who got black coffee, Izzy must have gotten black coffee.
Three people got espressos, and none of them are adjacent. (Lyle’s clue). No one in the first column got espresso (Izzy’s clue), and no column has the same five drinks, so the third and the fifth column each have an espresso, as well as either Grace or Polly. (It cannot be both Grace and Polly, since columns two and four have four drinks the same – the fifth one must be something different per Lewis’s clue).
If Polly had an espresso, the only person in the fifth column not adjacent to her is Ian. However, he cannot have an espresso as we know from George’s clue he had tea. Therefore Polly did not have espresso, but Grace did.
Since there are four people who got mochas (May’s clue), there must be a mocha in every column but the second (which is completely filled by this point), as each column cannot have multiple drinks of the same type. The only person without a drink already identified in the fourth column is Polly, so Polly had a mocha.
Grace is next to someone who had black coffee- it cannot be James or Sam, since someone in their column already has black coffee, and it cannot be Harry, since no one else in Art’s row had black coffee (Art’s clue). By process of elimination, it must be Joy.
Polly is adjacent to only one person who had a mocha. Either Jane or Peter in the fifth column must have had a mocha, and Polly is adjacent to both. This means that she is not adjacent to the person in the third column who had the mocha, so it must be Morgan.
Since no two people who got espressos are adjacent, neither James nor Sam got one, as they are adjacent to Grace. This means that Neal must have gotten an espresso.
There must be an espresso and a mocha in the fifth column, and since Ian is some type of tea, this must be Jane and Peter in some order. Patrick’s clue says Jane and Morgan got something different, so since Morgan got a mocha, Jane got espresso and therefore Peter got a mocha as well.
The two people who got hot chocolate are in the same row. This must either be Harry and Sam or Dave and Ian. Ian is some type of tea (George’s clue), so it can’t be him, and so must be Harry and Sam.
Dave got a mocha only if Jane did (Morgan’s clue), but Jane didn’t get a mocha, so neither did he. This leaves Greg as the only person in column one who could get a mocha.
The people next to Greg got four different drinks (Greg’s clue), so by process of elimination, Dave must be green tea. (There are already two black coffees next to Greg, so Dave must have gotten something that is not already next to Greg, which eliminates black coffee, chai tea or a latte, Hot chocolate and mocha are already included in the column, and all five drinks in each column are different (Lewis’s clue). This leaves just green tea)
Since more people got chai tea than green tea (Jane’s clue), both James and Ian must have gotten chai.