by myself:我自己;独自;单靠自己(常用来强调“没有别人帮助/陪同”,或强调“亲自完成”)。在日常口语中也常用 on my own 表达相近意思。
/baɪ maɪˈself/
I went to the store by myself.
我一个人去商店了。
She built the website by herself, learning everything by herself along the way.
她独自搭建了那个网站,并在过程中全靠自学掌握了所有东西。
by 原意有“靠……方式/手段、通过”的含义;myself 是反身代词(my + self),表示“我自己”。合在一起,by myself 就有“凭我自己/独自”的强调语气。类似结构还有 by yourself / by himself / by herself / by themselves。