I decide to spend(spend)as much time as I can studying (study)English.
第一空是【decide to do sth】的句型,用不定式
第二空你可以把【as much time as I can】看成插入语,主干就是【spend time doing sth】的结构,所以用动名词可是标准答案上给的是to study？纠结、应该是答案错了吧~