Complex sentence: He helped Arsenal reach the 1978 FA Cup Final, which they lost 1-0 to Ipswich Town, but differences with the Arsenal manager Terry Neill meant that he moved to the Seattle Sounders of the NASL for £100,000 at the age of 27.
Split into simpler sentences: He helped Arsenal reach the 1978 FA Cup Final, which they lost to Ipswich. Conflicts with the Arsenal manager Terry Neill meant that he moved to Seattle Sounders in the North American Soccer League for £100,000 at the age of 27.