she said the best way to learn new words was by reading English magazines
这是一个含宾语从句的复合句,主句是she said
the best way to learn new words was by reading English magazines.是宾语从句,既然是句子,英语中就得要有主语谓语,the best way to learn new words 是从句的主语,was by reading English magazines
构成谓语部分
而I study by making flashcards.是简单句,简单句的定义是：只有一个主语（或并列）和一个谓语（或并列）的句子叫简单句.
这位同学你题的问题挺好,要学好英语就的一点一点的学习,直至学会弄懂