The temporal adverbs yǐ jīng (已经) and zǎo yǐ(早已) signify the completion of an action or a change of state. Zǎo yǐ(早已) could be regarded as the abbreviation of the phrase hěn zǎo yǐ jīng (很早已经), which emphasizes that the completion of the action or had/ has/will have achieved long ago. Zǎo yǐ(早已) is used more in writing language and could be replaced by yǐ jīng(已经) in most cases. A sentence with yǐ jīng (已经) or zǎo yǐ (早已) usually has the perfective aspect particle le (了) , marking that the reported situation could be viewed as actualized by the reference time.
昨天我到家的时候他已经离开了。
zuó tiān wǒ dào jiā de shí hòu tā yǐ jīng lí kāi le.
He had already left when I got home yesterday.
这件礼服的样式早已过时了。
zhè jiàn lǐ fú de yàng shì zǎo yǐ guò shí le.
The style of this dress is outdated long ago.
明天这个时候我们可能已经在上海了。
míng tiān zhè gè shí hòu wǒ men kě néng yǐ jīng zài shàng hǎi le.
We may have arrived in Shanghai by this time tomorrow.
Besides being used to modify verbs, yǐ jīng(已经) also could be used before adjectives and numbers, and still translates to “already”.
这个成绩已经很好了。
zhè gè chéng jì yǐ jīng hěn hǎo le.
This result is already good.
他居然已经五十岁了。
tā jū rán yǐ jīng wǔ shí suì le.
He is already fifty years old.