Complex sentence: When Donald leaves the two alone in a bid to solve their almost definite financial collapse, James's condition begins to worsen, believing he is able to look after his sick mother rather than nurse Mary (Sarah Ball) who was sent by Donald.
Split into simpler sentences: When Donald leaves the two alone in a bid to solve their almost definite financial collapse, James's condition begins to worsen. He believes he is able to look after his sick mother rather than nurse Mary (Sarah Ball) who was sent by Donald.