Search results
Results from the WOW.Com Content Network
The word "perfect" in this sense means "completed"; it contrasts with the "imperfect", which denotes uncompleted actions or states. In English grammar, the pluperfect (e.g. "had written") is now usually called the past perfect, since it combines past tense with perfect aspect. (The same term is sometimes used in relation to the grammar of other ...
It can be proven that: . For a given prime number p, if n is p-perfect and p does not divide n, then pn is (p + 1)-perfect.This implies that an integer n is a 3-perfect number divisible by 2 but not by 4, if and only if n/2 is an odd perfect number, of which none are known.
The past perfect progressive (sometimes referred to as the past perfect continuous) combines had (the simple past of have) with been (the past participle of be) and the present participle of the main verb: You had been waiting. It is used to refer to an ongoing action that continued up to the past time of reference.
Resultative perfect (referring to a state in the present which is the result or endpoint of an event in the past): "I have lost my pen-knife" (message: I still don't have it) Continuative perfect (past situations continuing into present): "I have always guided him" Anterior perfect (completed past situations, but with relevance to the present):
Regular verbs have identical past tense and past participle forms in -ed, but there are 100 or so irregular English verbs with different forms (see list). The verbs have, do and say also have irregular third-person present tense forms (has, does /dʌz/, says /sɛz/).
The perfect, not the imperfect, is used when a situation is said to have lasted in the past for a certain length of time, but is now over. [69] (The imperfect, however, with a length of time, is used for a situation which was still going on at the time referred to; see the examples above.)
For instance, 6 has proper divisors 1, 2 and 3, and 1 + 2 + 3 = 6, so 6 is a perfect number. The next perfect number is 28, since 1 + 2 + 4 + 7 + 14 = 28. The first four perfect numbers are 6, 28, 496 and 8128. [2] The sum of proper divisors of a number is called its aliquot sum, so a perfect number is one that is equal to its aliquot sum.
The base form or plain form of an English verb is not marked by any inflectional ending.. Certain derivational suffixes are frequently used to form verbs, such as -en (sharpen), -ate (formulate), -fy (electrify), and -ise/ize (realise/realize), but verbs with those suffixes are nonetheless considered to be base-form verbs.