动词不定式（to do sth.)一般表将来时；动名词（doing sth.)一般表进行时,他俩有明显的时态差别,一般不可互换.
但若不强调时态,只是补充做句子成分,则可以互换,如：
To play football is my favorite.可换成 Playing football is my favorite.
二者可以互换使用.差别只在于to play表示具体的动作,playing表示通常的状态.如他喜欢玩儿,说He likes playing.他现在想玩儿了.He likes to play now.