This tutorial will help you understand the basic function of lexical access operators.

Note: this tutorial assumes that you have already started NL-Soar and know how to run a sentence.

Enter the sentence "the baby sneezed."
Run a few decision cycles until you see the lexical access operator for the first word (here we have first gone 7 decision cycles, then one more):

% d 7
0: ==>S: S1
     1:    O: O5 (execute-mission)
     2:    ==>S: S14 (operator no-change)
     3:       O: W4 (wait)
     4:       O: W4 (wait)
     5:       O: W4 (wait)
     6:       O: W4 (wait)
     7:       O: W4 (wait)

% d 1

Time has come for EnterWord 350 the...
50 Soar hears you say: the

8: O: A27 (access word: 'the' spkr: user)

Here an operator has begun firing which will access lexical, syntactic, and semantic information for the current word (in this case the word "the"). Note that there is currently no information displayed in the syntax and semantics grapher windows.
Run the system one decision cycle. Note that the syntactic information for this word is displayed in the syntax grapher window.
Run the system about 30 more decision cycles, and then step forward one decision cycle at a time until the next lexical access operator arises:

47: O: W9 (wait)

48: O: W9 (wait)

Time has come for EnterWord 350 baby...

400 Soar hears you say: baby

49: O: A56 (access word: 'baby' spkr: user)

Again, run the system one decision cycle. This time note that the syntactic information for this word is displayed in the syntax grapher window; this time it consists of a noun phrase node and its projections N-bar (written N') and noun-phrase (NP).
Continue processing the sentence until you see an access operator for the word "sneezed". Notice that this time a verb node (V) with its projections is created. In addition, an inflectional node (I) with its projections is also created, because NL-Soar considers this word as a potential sentence predicate.
Prepositions, adjectives, and other parts of speech behave similarly during lexical access: the word is categorized, and phrases are projected above the word when appropriate.
As you run other sentences with categories that are ambiguous between verbs and nouns (e.g. play) or other parts of speech, notice that all possible lexical categories are accessed, and corresponding phrases are built up during access.