Which preposition to use with doubtful

of Occurrences 99%

Seeing that the coast ran out to sea, the masters and pilots were in great confusion, and doubtful of standing out again to sea, saying that the land went across the sea and had no end to it.

as Occurrences 36%

If Gifford was doubtful as to the expediency of the plan, and it was with a considerable amount of hesitation that he brought himself to agree to it, he seemed to have no good reason to urge against it.

in Occurrences 29%

Canterbury grew because she was almost equally near to the ports we know as Lympne, Dover, Richborough and Reculvers, so that a man setting out from the continent and doubtful in which port he would land, wholly at the mercy of wind and tide as he was, would name Canterbury to his correspondent in England as a place of meeting.

about Occurrences 29%

But he began to feel more and more doubtful about the French Canadians, most of whom began to feel more and more doubtful about themselves.

to Occurrences 12%

" The matter, however, seemed still rather doubtful to Lippo.

for Occurrences 8%

Claims that have remained doubtful for ages cannot be settled in a day.

at Occurrences 8%

That it might not be doubtful at whose instigation this revolt was undertaken, Dunstan returned into England, and took upon him the government of Edgar and his party.

than Occurrences 4%

" He himself got a cab, too, and went off to Gresham Street, more puzzled and doubtful than ever.

on Occurrences 4%

It is, therefore, marked doubtful on the chart.

with Occurrences 3%

But the word resonance, being accented usually on the first syllable only, is naturally a dactyl; and, since the other five little verses end severally with a monosyllable, which can be varied in quantity, it is possible to read them all as being dactylics; and so the whole may be regarded as trebly doubtful with respect to the measure.

from Occurrences 2%

However, the verdict of divine and human law could never be really doubtful from the first, for the charges on which she was found guilty comprehended many grievous sins.

by Occurrences 2%

As this circumstance is agreed on by all, I am the more surprised that it should be doubtful by what road he crossed the Alps; and that it should commonly be believed that he passed over the Pennine mountain, and that thence

during Occurrences 1%

These numerous auxiliaries rendered Edward's army irresistible; and soon afterward the French and English fleets, both of formidable power, but the latter of inferior force, met near Sluys, and engaged in a battle meant to be decisive of the war: victory remained doubtful during an entire day of fighting, until a Flemish squadron, hastening to the aid of the English, fixed the fate of the combat by the utter defeat of the enemy.

through Occurrences 1%

There, by advice of Postumius, Minucius came to an engagement with the enemy; and when the fight had continued doubtful through a great part of the day, Postumius, with his fresh legions, made an unexpected attack on the enemy's line, spent by this time with fatigue: thus, weariness and wounds having rendered them incapable even of flying, they were cut off to a man, and twenty-one standards taken.

after Occurrences 1%

I did not want to go back to Persia, even if I could go there, which looked very doubtful after the battle of Salamis, and as I had come into the country with the Persians, it might have been unsafe to show myself with the Greeks; so, remembering what I had seen of the wild regions of Mount Athos, I made my way there, with the intention of dwelling in its rocky fastnesses until the country should become safe for the ordinary wayfarer.

Which preposition to use with  doubtful