You are missing some data here. How can you tell an actionid for an item has been completed when the first table doesn't have ItemIDs? You have two actionIds of "1" for different items.
Please also ask the question with DDL like this, so people can help you run tests.
CREATE TABLE ActionEmp
( ActionID int
, EmployeeResponsible int
)
;
go
INSERT ActionEmp SELECT 1, 12345;
INSERT ActionEmp SELECT 2, 67890;
INSERT ActionEmp SELECT 3, 54321;
INSERT ActionEmp SELECT 4, 09876;
go
CREATE TABLE Actions
( ItemID int
, ActionID int
)
;
go
INSERT Actions SELECT 1, 1;
INSERT Actions SELECT 1, 2;
INSERT Actions SELECT 2, 4;
INSERT Actions SELECT 3, 1;
INSERT Actions SELECT 3, 2;
INSERT Actions SELECT 3, 3;
GO
SELECT
a.ItemID
, ae.ActionID
, ae.EmployeeResponsible
from ActionEmp ae
LEFT OUTER JOIN Actions a
ON ae.actionid = a.actionid
ORDER BY
a.ItemID
, ae.actionid
;