Surely "in" on its own doesn't mean what it means as a morpheme either though? So you could argue that con- and -ceive <i>are</i> morphemes in English, since they appear with the same meanings in other words such as "concoct" and "receive".<br>Although, I suppose the reason they don't count as morphemes is that <i>neither</i> is a standalone word but together they <i>are</i> a word, suggesting they don't <i>properly</i> have meanings...