When connecting ideas with “and,” “or,” or “but,” they should be written in parallel form. This means using the same grammatical structure for each idea. Ideas that are equal in importance should be presented in parallel form. In this example, “Prolonged fever, together with subcutaneous nodules in a child, could be due to an infection with a Gram organism, but it could also be that the child suffers from rheumatic disease”, the sentence is not parallel, making it harder to understand. The second half of the sentence should be rewritten to match the grammatical structure of the first half, as shown here “Prolonged fever, together with subcutaneous nodules in a child, could be due to an infection with a Gram organism or due to rheumatic disease.”