SQL & PL/SQL :: Incorporate Two Counts In A Single Query?

User table

id | name
----------
2 | Harry
3 | Mary

Course_User table

summer_course_completed | winter_course_completed | user_id | attendance
------------------------------------------------------------------------
y | n | 2 | 20
y | n | 2 | 40
y | y | 2 | 30
n | n | 3 | 20
n | y | 3 | 60

I wish to list each student's name with the number of summer courses he has completed and the number of winter courses he has completed. I am trying this :

select u.name, count(*)
from user u, course_user cu
where u.id=cu.user_id and cu.summer_course_completed = 'y'
group by u.id;

but I can get only the number of summer courses OR the number of winter courses that each student has completed, but never both simultaneously, through a single query. Is there a way to do that ?