This incident happened in 2013 in Boston, USA. The JAL pilot appears to have strong English - he speaks fluently and clearly and uses good clarification techniques (“You mean fuel leak from left wing?”). The controller is empathetic and accommodates her rate of speech well (although in her attempts to be helpful some of her transmissions seem unnecessarily long and ‘wordy’). The communication goes well until Boston Command asks, “All passengers are all set?” The pilot resolves the problem well by asking “What does it mean, ‘set’?”