一直=keep 我一直在等待他的回复 wo yi zhi zai deng dai ta de hui fu I keep waiting for his reply.

Hi Elisa, 一直 is a little bit difficult to translate from Chinese into English. It means "from the beginning all the way to the end". Let's use your sentence as the example. （他是）我一直要找的主角 He is the leading actor that I have been looking for all this time Other examples 雨從早上一直下到晚上 It rained from morning until night 我一直在法國工作，五年沒有回過家 I have been working in France all this time, I haven't been home in 5 years 她一直生活在艱苦的生活環境 She has always lived in difficult circumstances Laurence

Keeping = 保持 is very different from 一直 Please don't give the wrong answer if you are not sure

一直=keeping