Language box · Reduced relative clauses — your rule, confirmed

The mechanism — delete who / which / that + be; the rest stays

Max, ~~who is~~ a designer ~~who is~~ making waves… · a collection ~~which was~~ inspired by his grandmother

It also works without be, for simple active verbs: students ~~who hope~~ → students hoping to launch their own brands.

-ing — the noun does the action active meaning survives

the teenager leading the cleanup (= who leads / is leading) · the only brand using deadstock fabric (= which uses) · anyone wanting to join (= who wants)

past participle — the action is done to the noun passive meaning survives

a record set at ten (= which was set) · an idea dismissed as childish (= which was dismissed) · a designer known worldwide (= who is known)

Self-check trick — restore the full clause and listen

Unsure between knowing and known? Restore it: “Max, who is knowing worldwide” ✗ vs “Max, who is known worldwide” ✓. The full clause never lies.