tā / zì jǐ / yán jiū / le / hěn jiǔ / zhēn shi / jiǔ bìng chéng yī / yǐ jīng / néng / gěi / bié rén / tí chū / zhuān yè / jiàn yì / le

他自己研究了很久，真是久病成医，已经能给别人提出专业建议了。

After studying it for a long time, he truly became an expert through experience and can now offer others professional advice.