Complex sentence: On 9 June a two-pronged British attempt to surround and capture Caen was defeated but on the right of the British Second Army, the 1st US Infantry Division had forced back the German 352nd Infantry Division and opened a gap in the German front line.
Split into simpler sentences: On 9 June, a two-pronged British attempt to surround and capture Caen was defeated. But on the right of the British Second Army, the 1st US Infantry Division had forced back the German 352nd Infantry Division, and opened a gap in the German front line.