自 + Time/Place + Verb
自 (zì) means "from" or "since" and is used as a preposition to indicate a starting point in time or place. It is more formal than 从 and is commonly seen in written Chinese and news reports.
自二〇二〇年起,这项政策就开始实施了。
zì èr líng èr líng nián qǐ, zhè xiàng zhèngcè jiù kāishǐ shíshī le.
This policy has been in effect since 2020.
他自北京出发,一路骑行到了上海。
tā zì Běijīng chūfā, yīlù qíxíng dào le Shànghǎi.
He set off from Beijing and cycled all the way to Shanghai.
自古以来,人们就对星空充满好奇。
zìgǔ yǐlái, rénmen jiù duì xīngkōng chōngmǎn hàoqí.
Since ancient times, people have been full of curiosity about the starry sky.