verb
ADVERB
▪ openly , publicly
▪
Commentators are openly speculating on whether the accusation is false.
▪ widely
▪ wildly
▪
The British press ~d wildly about his disappearance.
VERB + SPECULATE
▪ can only
▪ be free to , feel free to
▪
Both sides are free to ~ on the other's motives.
▪ decline to , refuse to
▪ be interesting to , be tempting to
▪ be possible to , be reasonable to
▪
It would seem entirely reasonable to ~ that tribal loyalties influenced the outcome of the election.
▪ be premature to
▪
It would be premature to ~ as to the outcome at this stage.
▪ be difficult to
PREPOSITION
▪ about
▪
There was no point in speculating about the possibility of them getting back together.
▪ as to
▪
We can only ~ as to this man's identity.
▪ on , upon
▪
He refused to ~ on her reasons for leaving.
Speculate is used with these nouns as the subject: ↑ newspaper