Connecting two queries to get Cartesian product

I have a query

SELECT 
d.GUID, w.word
FROM
dictionary d
    JOIN
word w ON w.ID = d.ID_word
WHERE
w.id_language = #ID#;
    

if #ID# = 1 it returns table

GUID | word
-----------
1    | A
2    | B
3    | C1
3    | C2
4    | D1
4    | D2
5    | E

if #ID# = 2 it returns table

GUID | word
-----------
1    | AA
2    | BB1
2    | BB2
3    | CC
4    | DD1
4    | DD2
6    | FF

Now I want merge these two tables/queries to get a table which looks like that:

GUID | word1 | word2
--------------------
1    | A     | AA
2    | B     | BB1
2    | B     | BB2
3    | C1    | CC
3    | C1    | CC
4    | D1    | DD1
4    | D1    | DD2
4    | D2    | DD1
4    | D2    | DD2

So basically it is a table of the Cartesian product of the rows with the same GUID

Answer

You don’t need subqueries:

SELECT d1.GUID, w1.word, w2.word
FROM dictionary d1 JOIN
     word w1
     ON w1.ID = d1.ID_word JOIN
     dictionary d2
     ON d2.GUID = d.GUID JOIN
     word w2
     ON w2.id = d2.ID_word
WHERE w1.id_language = ? AND
      w2.id_language = ?;

I think this is more readable using CTEs:

WITH dw AS (
      SELECT d.GUID, w.word, w.id_language
      FROM dictionary d JOIN
         word w
         ON w.ID = d.ID_word
     )
SELECT dw1.GUID, dw1.word, dw2.word
FROM dw dw1 JOIN
     dw dw2
     ON dw1.GUID = dw2.GUID
WHERE dw1.id_language = ? AND
      dw2.id_language = ?;

In both these examples (and what is implied by your question) GUIDs with only one word are filtered out. These can be included by tweaking the queries.