Sulla base di questa domanda e delle tue domande precedenti, penso che potresti cercare qualcosa del genere:
SELECT u.name_surname,
u.avatar,
GROUP_CONCAT(DISTINCT w.word Order by w.word asc) AS words
FROM users u
INNER JOIN
(
SELECT f1.asker_user_id AS friend_id
FROM friends AS f1
LEFT JOIN friends AS f2
ON f1.asked_user_id = f2.asker_user_id
AND f1.asker_user_id = f2.asked_user_id
WHERE f1.status = 1 AND f2.status IS NULL
AND f1.asked_user_id = 2
) a ON a.friend_id = u.id
LEFT JOIN connections c ON u.id = c.user_id
LEFT JOIN words_en w ON w.id = c.word_id
GROUP BY u.id;
