perfective aspect vs plain

perfective aspect

noun
  • A feature of the verb which denotes viewing the event the verb describes as a completed whole, rather than from within the event as it unfolds. For example, "she sat down" as opposed to "she was sitting down". Since the focus is on the completion of what is expressed by the verb, this aspect is generally associated with the past and future tenses. This term is often used interchangeably with aorist aspect. This is not to be confused with the perfect tense. 

plain

noun
  • A lamentation. 

  • An expanse of land with relatively low relief, usually exclusive of forests, deserts, and wastelands. 

adv
  • Simply. 

adj
  • Downright; total, unmistakable (as intensifier). 

  • Clear; unencumbered; equal; fair. 

  • Not a trump. 

  • Containing no extended or nonprinting characters (especially in plain text). 

  • Not unusually beautiful; unattractive. 

  • Evident to one's senses or reason; manifest, clear, unmistakable. 

  • Honest and without deception; candid, open; blunt. 

  • Simple in habits or qualities; unsophisticated, not exceptional, ordinary. 

  • Ordinary; lacking adornment or ornamentation; unembellished. 

  • Having only few ingredients, or no additional ingredients or seasonings; not elaborate, without toppings or extras. 

  • Of just one colour; lacking a pattern. 

How often have the words perfective aspect and plain occurred in a corpus of books? (source: Google Ngram Viewer )