- encode grammatical properties

 - present tense inflection : -s
 - past tense inflection : -ed
 - any word that can take tense inflection is a verb

- finite V carries tense
 - nonfinite V doesn't carry tense

 - 3rd person singular ending : -s

Main V (lexical V)
 - can stand on their own in a sentence

Auxiliary V
 - cannot occur independently (must accompany another V (main V)
 - adds more specific meaning to the main V (specifies from what point of view we should view the meaning expressed by the main V)

Modal Auxiliary V
 - can/could, may/might, must, ought to, shall/should, will/would
 - ability, permission, possibility, obligation, necessity, intention, prediction, ...
 - modal meaning - concerned with expressing situation
 - color the meaning of the verbs they precede
 - always finite
 - no endings

Aspect Auxiliary V
ex)These students are always complaining.
ex)Shelly has broken two wine glasses.
 - encode aspect, a concept which refers to the way the meaning of the main V is viewed in time
 - be : progrssive aspect - ongoing process, certain duration
 - have : perfective aspect
1 take place in the past and has current relevance
2 present perfect (have + past participle) / past perfect (had + past participle)

Passive Auxiliary V
ex) This doughnut was eaten by our Head of Department.
 - be + p.p.
 - always followed by a main V ending in -ed (past participle form of the V)

 - add the negative particle 'not' after the first aux.

Dummy Auxiliary V : do
ex)Do you like dating doughnuts?
1 do-support : negation 에서 aux. 없을 때 do + not
2 Subject-Auxiliary inversion : interrogation 에서 aux. 없을 때 do 가 대신
3 code : occurs without its main V
ex) Does John cycle to work every day? he does.
ex) Jon cycles all the way to work every day, and so does Tim.
4. emphatic contexts
ex) He DOES killed her.

Auxiliary V - NICE
1 carry the negative enclitic particle not
invert with the S
3 manifest code
4 carry emphatic stress

 - be + being + p.p. : progressive + passive
 - have _ been _ p.p : perfective + passive

 - it is always the first aux. that carries tense
 - all the other verbs are nonfinite
 - finite V forms occur either in the prsent tense or in the past tense

Nonfinite verb-forms
 - to-infinitive
ex) I wanted him to dance.
 - bare infinitive
ex) I saw him dance.
 - present participle
ex) He is dancing.
 - past participle
ex) He has often danced.

1 be careful not to confuse the past participle with the past tense form
2 aux. determines the form of the main V
progressive aux. be + Ving (present participle)
passive aux. be + p.p. (past participle)
3 strict order of  aux.s
modal - perfective - progressive - passive
4 negative particle 'not' always follows the first aux.

 - VP can contain NP which has DO function
ex) The Library recalled these books.