Preposition: that

• anyone: It's doubtful that anyone here today knows less about the day to day realities of running a school than I do!

Modifies a noun

• legality: The Government built its case on unreliable intelligence, in circumstances of doubtful legality.

• provenance: Or, of course, with no UK agriculture at all - only imported food of doubtful provenance and a rural Theme Park.

• authenticity: It has been claimed that the words of our Lord in Luke 21: are of doubtful authenticity.

• validity: PA reiterated that the whole notion of 'learning styles ' was of doubtful validity.

• debt: The decision to take legal action, to recover a doubtful debt, will be determined on a case-by-case basis.

• glance: She cast a hurried and doubtful glance over her attire.

Modifying Another Word

• extremely: His own work on micro economics makes him extremely doubtful.

• somewhat: The policy of enclosing stops voiced in such a refined manner on so low a wind pressure is somewhat doubtful.

• highly: Whether these hadiths actually stem from the time of Muhammad is highly doubtful.

• rather: With one rather doubtful exception he can't find a single credible connection.

• equally: I am equally doubtful whether these approaches can be combined with genuine decentralization.

• very: A lot of things you do make me very doubtful.

Used with adjective complement

• seem: Whether there was ever any strong likeness to any building in or near Whitby seems doubtful.

• appear: The researchers appear doubtful about their results due to species differences, stating: " inevitably there are several distinct differences.

• remain: The very idea of a ' logic ' in the history of ideas remains quite doubtful to me.

• look: With Norton's participation in the rest of the event now looking doubtful, Watkins now had a shot at the class victory.

• consider: Louis Saha is also considered doubtful for the game.

Preposition: with

• injury: Ty Smith is doubtful with the foot injury he sustained at Braintree.

Preposition: for

• tomorrow: John Hartson is also doubtful for tomorrow, so we will likely see new Bhoy Henri Camara and young Craig Beattie pairing up-front.