By far we have learned that roots can be strengthened to higher levels when new words are created. However, not all verbs can do so. Some verbs cannot be strengthened to more than medium level. Those verbs are “nind”, “jiv” and “cint”
These verbs cannot be strengthened to the highest level because they are already heavy syllables, which mean that they are heavy syllables with an extra consonant. This means that if we remove the consonant, we are still left with heavy syllable.
The reason why this happens is that in many primary suffixes, the verb roots need to be strengthened to the medium level. Thus, nind becomes nindana, jiv becomes jivana and jay become jayana. Double heavy roots become itva instead of tva.