He's 16, but he often seems (to be) younger.
I suspect his claims are not all they seem - he tends to exaggerate.
Things are seldom as/how/what they seem.
[ + to infinitive ] I seem to know more about him than anyone else.
[ + (that) ] It seems (that) she can't come.
formal It would seem (that) no action need be taken.
[ after so ] "There's no reply - they've all gone home." "So it seems."
"Was a decision made?" "It seems not/so."