I know that when looking for a splitting pattern you need to know the number of hydrogens on the 'neighbouring' carbon atom. Is that the carbon on the right hand side, or on the left hand side? As each side produces a different pattern.
Like if the question was, what splitting pattern does the CH2 in CH3CH2COOH produce, would I be looking at the number of H's on the neighbouring C atom on the LHS or RHS?