# 10.3: §70. The Perfect Participle as 4th Declension Noun

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Just as Latin could turn the neuter (-um) form of the perfect participle into a 2nd declension noun, so could it convert the masculine (-us) form into a regular 4th declension noun. There was originally a contrast between these two, in that the neuter noun was felt to be concrete and the masculine somewhat more abstract; but that contrast is often hard to discern in practice. These fourth declension nouns look exactly like the perfect participle—sensus, ductus, tractus, etc. They are quite numerous, and easy to identify.

Here is a sampling of 4th declension Latin nouns that were derived from perfect participles of verbs. Some of them come from verbs that we met in the last chapter, while others will be less familiar:

 LATIN VERB LATIN NOUN ENG. NOUN (ADJ.) agere, actus (“do”) actus (“a doing) act [1] (actual) cadere, casus (“fall”) casus (“a falling”) case [2] (casual) censēre, census (“reckon”) census (“a reckoning”) census ducere, ductus (“lead”) ductus (“a leading”) duct exire, exitus (“go out”) exitus (“a going out”) exit labi, lapsus (“slip,” “slide”) lapsus (“a slipping”) lapse sentire, sensus (“feel”) sensus (“a feeling”) sense (sensual) stare, status (“stand”) status (“a standing”) status, state trahere, tractus (“drag”) tractus (“a dragging”) tract uti, usus (“use”) usus (“a using”) use (usual)

Several forms of this type, with prefixes attached, have come into English completely unchanged. We have already seen that a consensus is “a shared feeling.” What are the etymological meanings of conspectus and prospectus? (Like status and state, prospectus and prospect are English doublets.) Convent and congress come from the semantically similar Latin nouns conventus and congressus.

1. This English word is thought to derive both from the neuter noun actum and the masculine noun actus. The influence of the 4th declension actus is seen in the English adjective actual (< actu-alis). ↵
2. There are two English homographs of this form; E case = “a container” comes from L capsa (whose diminutive capsula is the source of capsule). ↵

10.3: §70. The Perfect Participle as 4th Declension Noun is shared under a CC BY license and was authored, remixed, and/or curated by Peter L. Smith (BCCampus) .