this two word always use together:更多

First, correction. 我要多学习 （it's ok, but it sounds not very native. It seems something is missing here.) => 我要多多学习。 OR 这书写得很好，我要多学习（这本书的内容）. 我要多学习 needs an object!. 我要多学习。你要多学习啥？ 我要更学习 (it is NOT correct.) => 我更（加）要努力得学 OR 我要学得更（加）努力。 更 is used to strengthen Adj. or Adv., not Verb. For example, For Adj. 她那件裙子我觉得更漂亮 (I think her skirt is more beautiful.) For Adv. 我跑得比你（更）快。 I run faster than you. -------------------------------------------------------------------------------------------------------- In a word, 多 is like many (generally) or more (in quantity, many 的比较级) or more often (just like the first case you mentioned). 更 is like more (+adj./adv.) in English. -------------------------------------------------------------------------------------------------------- Back to your question, how to translate "I need to learn more." 我得多学点。( I think you probably want to express this meaning. It implies or emphasizes that I need to learn more things not in time (more often) or not more hard but in quantity.) Besides, 我要 = I want (In German, Ich will. If you can German, it would help. If not, it is ok.) 我得 = I need to (becasue something for example pressure drives me, and I should or have to do something) For example, 今晚我得早点睡。I need to go to bed early tonight (maybe I need to go to work or school tomorrow)

我得更精進。 精進 佛教用語。指在修善、斷惡、去染、轉淨的修行過程中，不懈怠的努力。 今取其專心向學，努力不懈之意。

多表示more，后面一般是接中文的动词或者修辞词，例如多学习，多运动和多高，多大，多长等等，更后面一般是接中文的修饰词，例如更加美好，更远，更高，更强等，更后面接动词读起来很别扭，例如更学习，更运动

我要加倍努力学习. 通常表study more, 就用 加倍表示.