If anyone could help me with part 4-5-6-7

Write a phrase structure grammar that generates {(ab)n:n0} Write a phrase structure grammar that generates {(ab)n:n1} Write a phrase structure grammar that generates {anbn:n1} Write a phrase structure grammar that generates {anbncn:n1} Write a type-3 grammar that generates {(ab)n:n1} Write a type-2 grammar that generates {anbn:n1} Write a type- 1 grammar that generates {anbncn:n1}