II. Grammar

The following sentences illustrate the six parts of speech:

   fahrenheit=: 50
   prices=: 3 1 4 2
   orders=: 2 0 2 1
   orders * prices
6 0 8 2
   +/1 2 3 4 5
1 3 6 10 15
   bump=: 1&+
   bump prices
4 2 5 3
50 fahrenheit       Nouns/Pronouns
+ - * % bump Verbs/Proverbs
/ Adverbs
& Conjunction
( ) Punctuation
=: Copula

Verbs act upon nouns to produce noun results;
the nouns to which a particular verb applies are
called its arguments.
A verb may have two distinct (but usually related) meanings
according to whether it is applied to one argument (to its right),
or to two arguments (left and right). For example, 2%5
yields 0.4 , and %5 yields 0.2 .

An adverb acts on a single noun or verb to its left.
Thus, +/ is a derived verb (which might be called
plus over) that sums an argument list to which it is applied,
and */ gives the product of a list.
A conjunction applies to two arguments, either nouns or verbs.

Punctuation is provided by parentheses that specify the sequence of
execution as in elementary algebra; other punctuation includes
if. do. end. as discussed under
Explicit Definition (:) and
Control Structures.

The word =: behaves like the copulas “is” and “are” in English,
and is read as such, as in “area is 3 times 4”
for area=: 3*4 . The name area thus assigned is a
pronoun and, as in English, it plays the role of a noun.
Similar remarks apply to names assigned to verbs, adverbs, and conjunctions.
Entry of a name alone displays its value.
Errors are discussed in
Section II.J (Errors and Suspension).