The word "share" often comes up when people own things together, or when another person has or owns something and then gives it to another person to use or keep.
In these sentences and questions, "share" is a verb:
Bob shared his lunch with Martha because she forgot to bring something to eat.
The mother told her son to share with the other children the toys that he brought to the beach.
I have some information that I’d like to share with you.
Bill and Rosa share the cooking and cleaning responsibilities around the house.
Responsibility for the accident was shared by the two drivers who were involved. (This sentence is in the passive voice.)
Can you share a book? I don’t have enough books for all of the students.
Do you mind sharing? (In this question, "sharing" is a gerund.)
It’s feels good to share with others.
In the next set of sentences, "share" is a noun:
A large share of her salary goes to pay for rent. (share = a part, a portion)
A growing share of commuters are choosing to get to work by bike.
A much smaller share of the American public is opposed to racial integration compared to the past.
Don owns several hundred shares of Coca Cola. (People who invest in the stock market buy ownership in publicly-traded companies. These are called "shares." Most Americans own shares of stock in one form or another.)
The word "shared" is an adjective:
A shared set of values is what keeps their relationship strong.