两种说法都可以
1 I must do my homework
2 I have to do my homework
第一个主观意愿强些 也就是自己觉得必须要做作业
第二个是客观上的必须 也就是说由于别的一些客观原因 如老师家长要求你 必须做作业
I must do my homework.
I gotta do/finish my homework.(美式口语)
I must do/finish my homework.
I have to dofinish my homework.
I have to do my homework.