Use 'mainly' when you want to say that something is mostly or primarily about one thing. It shows the main focus or part of something.
She cooks mainly Italian food.
The book is mainly for children.
Use 'mainly' to explain the main reason or cause for something. It shows why something happens most of the time.
The change is mainly due to new laws.
He moved mainly for his job.
'Mainly' here shows the largest or most common part of something in science or technical talk. It describes what something contains mostly.
The planet is mainly made of gas.
The solution is mainly water.
Use 'mainly' to say who or what has the main role or is most important in a situation. It points to key responsibility or focus.
He is mainly responsible for the project.
The event is mainly about helping people.
'Mainly' can describe the most common style or influence in music or art. It shows what kind of style is mostly there.
The song is mainly jazz with some blues.
Her paintings are mainly abstract art.
