construct vs speculate

construct is a noun but speculate is not a noun.

Word	Noun	Adjective	Verb	Adverb
construct	Yes	No	Yes	No
speculate	No	No	Yes	No

As verbs, speculate is a hypernym of construct; that is, speculate is a word with a broader meaning than construct:

Other hypernyms of construct include conjecture, hypothecate, hypothesise, hypothesize, suppose, theorise, theorize.

construct (noun)	speculate (noun)
an abstract or general idea inferred or derived from specific instances

construct (verb)	speculate (verb)
reassemble mentally	reflect deeply on a subject
draw with suitable instruments and under specified conditions	to believe especially on uncertain or tentative grounds
make by combining materials and parts	talk over conjecturally, or review in an idle or casual way and with an element of doubt or without sufficient reason to reach a conclusion
put together out of artificial or natural components or parts	invest at a risk
create by organizing and linking ideas, arguments, or concepts
create by linking linguistic units