Should my teenage children have a tutor?

A mother of three asked me if I thought her children should have an English tutor. This is my answer:

As a native English speaker and English tutor, I have found that there are three groups of young people who particularly benefit from tutoring in English.

1. There are many young people who have grown up in Canada but whose parents speak little or no English. As a result, the children have learned most of their English from other children. They have a Canadian accent and no-one would guess that their knowledge of English is incomplete. They tend to have a small vocabulary and little knowledge of idioms. A tutor can fill in these gaps.

2 There are many young people who have studied English for many years in their
home country. Their knowledge of grammar is usually greater than that of the average native speaker and they have a big vocabulary. They can read at a sophisticated level but their ear is not yet tuned to the Canadian accent and they have trouble making themselves understood. They can be helped by intensive pronunciation and listening work.

3 There are young people graduating from high school or college who have a good grasp of social and academic English but who are not familiar with the English used in the workplace or in job interviews. They do not know how to describe their accomplishments. They can be helped by a Business English tutor