e can use preparatory it in cleft sentences. The emphasized words are usually joined to the relative clause by "that"
- It was the water that causes the disease.
- It was religion that the middle eastern people are fighting for.
- It was the facade that makes our house attractive to people.
using negative sentence with this structure is also possible
- It wasn't him that spreads the false rumors it was the secretary.
- It wasn't the window that Jeff broke.
"Who" is possible instead of "that" when a personal subject is emphasized.
- It I who initiated the protest.
- It is him who gave instructions to the people.