自...以来 and 由...组成

Pattern

time frame and composition frames

Use this HSK 5 pattern to make sentence structure, scope, or emphasis explicit instead of relying on word-for-word English order.

自从毕业以来，他一直很忙。

When to use 自...以来 and 由...组成

Read time frame and composition frames as a sentence tool, not just as vocabulary. First locate the main action or claim, then ask what 以来 adds to it.

这个句子里的以来让意思更清楚。

The 以来 in this sentence makes the meaning clearer.

如果不用以来，句子的重点会不一样。

Without 以来, the sentence focus would be different.

他说得很自然，因为他知道以来的位置。

He spoke naturally because he knew where 以来 belongs.

Common traps

Do not translate time frame and composition frames mechanically from English; check the Chinese word order first.
Keep 以来 close to the part of the sentence it controls.
Do not overuse the pattern in every sentence; use it when it adds a clear role.