How do I say "if I don't study, I cannot learn"?
&quot;study&quot; emphasizes the process of obtaining/ seeking knowledge (e.g. study math all night, not learn math all night).
&quot;learn&quot; emphasizes the process of receiving knowledge (e.g. learn how to fight from someone, not study how to fight from someone).

&quot;If I don't study, I cannot learn&quot; sound odd because it lack an object. If it has an object, it would be a more complete sentence.
E.g. If I don't study (mathematics), I cannot learn (mathematics) -- 如果我不学习(数学)，我就不会学懂(数学).

If you think 学习 and 学懂 are still too similar. You can replace &quot;学习&quot; (study) with &quot;学/ 去学&quot; (study); or replace &quot;学懂&quot; (learn) with &quot;懂&quot; (know/ understand).
Example:
&quot;不去学就学不懂&quot; - &quot;cannot learn if you don't study&quot;
&quot;不学就不会懂&quot; -  &quot;would not know/ understand if you don't study&quot;
More example:
&quot;去学就会学懂&quot; - &quot;can learn if you study&quot;
&quot;学就会懂&quot; - &quot;would know/ understand if you study&quot;