The article "du"
The article "du" is the contraction of "de + le". If it can be replaced by "un" or "de mon", it is the article.
- Il vend du pain.
- Il faut du sucre pour le gâteau.
- La voiture du directeur est rouge.
Past participle of verb "devoir": dû
"dû" with a circumflex accent is the singular masculine past participle of the verb "devoir". It carries the accent so as not to confuse it with the article "du". If it can be replaced by "requis" or "été contraint de" (was compelled to), then it is the verb devoir.
- Le travail est dû pour février.
- Il a dû arrêter ses travaux.
The other forms of the past participle of "devoir" do not have a circumflex accent because there is no danger of confusing it.
- Les sommes dues
- La tâche est due pour demain.
- "du" is an article which means "de + le"
- "dû" is the masculine past participle of verb "devoir"
- In the feminine or plural, there is no circumflex accent on the past participle of "devoir": due, dus et dues.