The participle is generally obtained from the basic stem by prefixing "e-" or "i-" (there is no rule; if the stem begins with a vowel, "j-" is prefixed instead), and suffixing "-i" (to stems ending in a consonant) or "-n" (to stems ending in a vowel). Occasionally there is no suffix. The verbal noun stem, another non-finite form, is obtained by replacing the suffixes "-i" and "-n" (and also "-tu" or "-du", see below) of the participle by either "-tze" or "-te". A third non-finite form which we shall call the "short stem" is obtained from the participle by omitting any of these suffixes except "-n", which is retained in the short stem in those verbs whose participle has it.