按照你所给句子,只能这样理解才可能正确：
If you're a visual learner,chances are 【that引导表语从句,省略】you did well on spelling tests,and so you have a sense of the rightness of spelling.
句子结构划分：
【If you're a visual learner条件状语从句】,【chances】【 are 】【（that）you did well on spelling tests表语从句】,【and so you have a sense of the rightness of spelling 并列句】.
句子意思：
如果你是一个视觉型学习者,可能你在拼写测试中曾做得很好,因此（可知）你有拼写的正确感.
祝你开心如意!