with sentences as
(
select 'short sentence' as sentence UNION ALL
select 'This is a nice dress' as sentence UNION ALL
select 'The quick brown fox jumped over the lazy dog' as sentence
)
SELECT
SUBSTRING(sentence,
CHARINDEX(' ', sentence,CHARINDEX(' ', sentence, CHARINDEX(' ', sentence)+1)+1),
LEN(sentence)) AS WordFourOnwards
FROM sentences
WHERE patindex('[^ ]% [^ ]% [^ ]% [^ ]%',sentence) > 0