words for Cause, reason, purpose, and result

A. Cause and reason

Owing to/ Because of the icy conditions, the two trucks collided.
The collision was due to the icy conditions.
The collision was caused by ice on the road.
The cause of the collision was ice on the road.

The cuts in social services sparked (off)/ignited a new round of bitter protests.
[often used for very strong, perhaps violent, reactions to events]
The President's statement gave rise to/ provoked/ generated a lot of criticism.
[ not as strong as spark or spark off]
The peace talks have brought about/ led to a cease-fire. [often used for political/social change]
Unemployment in the region stems from the steady decline in manufacturing jobs. [ explaining the direct origins of events and states]
The court case arose from allegations made in a newspaper. [ the allegations started the process that led to the court case]

B. Reasons for and purposes of doing things
Her reason for leaving her job was that she was offered a better position at another company. or The reason she left her job was that... [reason/cause]
I wonder what his motives were in sending that letter. [purpose]
I wonder what prompted him to send that letter. [reason/cause]
She wrote to the newspaper with the aim of exposing the scandal. [purpose]
She refused to answer on the grounds that her lawyer wasn't present. [reason]
The purpose of his visit was to establish goodwill.

C. Results
He didn't study. As a result/Therefore / As a consequence/ Consequently, he failed his exams.
The result/ consequence of all these changes is that no one is happy. [The examples with consequence/ consequently sound more formal than result.]
His remarks resulted in an explosion of anger. [ as a verb + in]
The meeting had an outcome that no one could have predicted. [result of a process or events, or of meetings, discussion, etc.]
The upshot of all these problems was that we had to start again. [less formal than outcome]