Use the verb "develop" when describing something that has changed, grown, or increased over a period of time.
Terry developed a headache from looking at a computer monitor all day.
It took several years for the trees to develop, but now they are mature and healthy. (develop = grow)
Walter is developing into a fine young man.
The city is developing a vacant lot and turning it into a park. (develop = construct; rebuild)
Facts and information about the news story are still developing.
The snowstorm developed into a big problem for travelers. (The snowstorm became a big problem.)
Left on the ground, these acorns could one day develop into large oak trees.
You can add "ment" to form the noun, "development."
There’s a new housing development planned for the city.
This is an interesting new development in the legal case against the defendant.
Haruna is taking early childhood development classes because she wants to work with children.
Note: The word "develop" was once commonly used for film cameras, before digital cameras became popular. After taking a roll of film, the images on the roll were developed by a company that had access to equipment and chemicals for developing the film. Film is still developed today, but not nearly as frequently as was the case prior to the arrival of personal computers and digital technology.