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.
zuó tiān wǒ dào jiā de shí hòu tā yǐ jīng lí kāi le.
He had already left when I got home yesterday.
zhè jiàn lǐ fú de yàng shì zǎo yǐ guò shí le.
The style of this dress is outdated long ago.
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”.
zhè gè chéng jì yǐ jīng hěn hǎo le.
This result is already good.
tā jū rán yǐ jīng wǔ shí suì le.
He is already fifty years old.