英语：have trouble/problems/difficulty加动词ing还是to do还是done

英语：have trouble/problems/difficulty加动词ing还是to do还是done
什么时候动名词做主语什么时候动词ing做主语
什么时候动词原形做主语
形式主语形式宾语什么区别
模棱两可,不懂装懂的谢绝回答

一、句子的主语一般可以由→
1.名词【 Mr.Chen】 is a well-known scientist.
2.代词【He】 works very hard at school.
3.不定式【To go to a good university】 is his first goal.
4.动名词【 Doing morning exercise 】is good for your health.
5.从句【What she saw 】made her a little frightened.
二、要注意的是,动词不能充当句子的主语!如 Go to college is my dream,这句就错,应该改成To go to college.
再问： ���to go to a good university �ɲ����Ը�Ϊ going to a good university��
再答： �ҵ�����Dz����԰ɡ���������Ϊ��my dream���ûʵ�֡���to�IJ���ʽ����ʾһ�ֽ���������
再问： �������ޣ��������� ���ʲ���ʽ�?�� ���ش�һ����ʽ�����ʽ����Ĺ���ʲô�İɡ����� ���Ҳ˵˵��ֱ�Ӳ��ɣ�
再答： ������it �����������дʣ���Ϊ������ʽ�ϵ�����������������Ƶ����Ӻ�ȥ�����ʹ���ӱ�ø�ƽ�ȣ�����ͷ�ؽ��ᡣ����it��Ϊ����������Ƶ����Ӻ�ȥ�����������Dz���ʽ������ν��������漸�����ͣ�a�� be+���ݴ�/���/��ʶ���+����ʽ���磺 �������ֱ����It��s easy to criticize others.���������������׵ģ��Ƚϣ�To criticize others is easy.�� ����It was his duty to take care of the orphans.���չ˹¶������ְ�� ����It��s beyond me to say why.�����޷�˵��ԭ�� ����b�����ﶯ��+����+����ʽ ����It takes two to make a quarrel.���裩����Ҫ�������� ������it�����б�������������ı���ŵ����Ӻ�ȥ���ر�������һЩ���ϱ����С�it���ԣ� ����1����?��ʽ�� She found it difficult to convince him. ����2�����that��ĴӾ䣨that��ʱʡ�ԣ��� ����I took it for granted ��that��you would be coming. ������ֻ���﷨���ϴ���һЩ��ȥ���ⷽ����Ҫ�˽������Դ����ϰ������﷨���ϲ����˽⡣