since (a time)自从 (or just from从) marks a starting point in past time — "ever since." since (a time)自从 is the more formal of the two, and the clause often closes with after以后 or to rise起.
Structure: 自从 + Starting Point ,……
ever since自从coming to来到Hunan湖南I,我more and more越来越can能take spice吃辣了。
Ever since I came to Hunan, I can take more and more spice.
ever since自从he他left走了以后the company,公司better好多了。
Ever since he left, the company's much better.
Remember: ((bound form) self自)from从 = the START POINT ("ever since…"); since (a previous event)以来 = the PERIOD running from it. since (a time)自从he / him他to walk走(completed / change)了 ("since he left") sets the point; …since (a previous event)以来 stresses the span up to now. since (a time)自从 is the formal one.
Watch out
- The clause often closes with after以后 / to rise起 — since (a time)自从…after以后, marking the start clearly.