Morphemes by numbers

One of the most commonly used sets of morpheme are numbers. For historical reasons English, like most continental languages, keeps a handy set of Latin and Greek numbers around just because they are so damned useful.

numbers In Greek examples
1 eis, mia, ev; mono- monologue, monopoly
2 duo; dis (di-) diameter, duet
3 treis, tria; tris (tri-) tripod, triple
4 tettares, (tetra-) tetradactyl, tetra- (many chemical compounds)
5 pente; (penta-) pentangle, pentateuch, pentalhlon
6 hex (hexa-) hexagon
7 hepta (hepta-) heptathlon
8 okto (okta-) okta (1/8 of sky covered in cloud)
9 ennea  enneagon
10 deka (deka-) decathlon, decahedron, decalogue
1000 khiloi (kilo-) kilogram, kilometre
Numbers In Latin (Roman) examples
1 unus, una, unum (uni-) unit, uniform, union, university
2 duo, dua (do-) duet, dual
3 tres, tria (tri-) trio, treble, tripod
4 quattuor (quadr-) quadrangle, quadruped
5 quinque (quint-) quintessence, quintet
6 sextus (sex-) sextet
7 septem (septa-) September (once 7th month!)
8 octo (octa-) octave, octagon, October (now 10th month!)
9 novem (nona-) November (once 9th month)
10 decem (deca-) decimal, December (once 8th month)
100 centum (centa-) century, centennial, percent
1000 mille (milla-) million, millenium
1/10 deci- decimal, decimate
1/100 centi- centimetre, centigrade
1/1000 milli- millimetre, milligram


You’ll find that 2000 years ago the very neat numbering system for months of the year was upset because  an extra couple of months were stuck in to partially correct the maths and coincidentally to celebrate two local big shots: July for Gaius Julius Caesar; and August for his nephew, Gaius Octavian, called Caesar Augustus.