1.tree：主语
turn：谓语
green：状语
when spring comes：整个是状语从句,when是引导词,spring是从句里的主语,comes是谓语
2.it是形式主语,代指to talk to you
is是谓语,比较特殊,是系动词
great pleasure 是表语
to talk to you 是真正的主语