List of auxiliaries in English Diagnostics for identifying auxiliary verbs in English

AUXILIARY VERBS
PLAN

1. 
   What’s Auxiliary Verb 
   

2. List of auxiliaries in English

3. Diagnostics for identifying auxiliary verbs in English

An auxiliary verb (abbreviated aux) is a verb that adds functional or grammatical meaning to the clause in which it occurs, so as to express tense, aspect, modality, voice, emphasis, etc. Auxiliary verbs usually accompany an infinitive verb or a participle, which respectively provide the main semantic content of the clause.^[1] An example is the verb have in the sentence I have finished my lunch. Here, the auxiliary have helps to express the perfect aspect along with the participle, finished. Some sentences contain a chain of two or more auxiliary verbs. Auxiliary verbs are also called helping verbs, helper verbs, or (verbal) auxiliaries. Research has been conducted into split inflection in auxiliary verbs Below are some sentences that contain representative auxiliary verbs from English, Spanish, German and French, with the auxiliary verb marked in bold:
a. Do you want tea? – do is an auxiliary accompanying the infinitive, want, used here to form a question – see do-support.
b. She has given her best shot. – have, from which has is inflected, is an auxiliary used in expressing the perfect aspect of give.
c. He cogido tu lápiz. – he is an auxiliary accompanying the infinitive coger, used here to form a verb phrase, the perfect present in Spanish.^[3]
(I) have grabbed your pencil = 'I have taken your pencil.'
d. Das wurde mehrmals gesagt. – werden, from which wurde is inflected, become is an auxiliary used to build the passive voice in German.^[4]
That became many times said = 'That was said many times.'
e. Sie ist nach Hause gegangen. – sein, from which ist is inflected, 'be' is an auxiliary used with movement verbs to build the perfect tense/aspect in German.^[5]
She is to home gone = 'She went home/She has gone home.'
f. J'ai vu le soleil. – avoir, from which ai is inflected, 'have' is an auxiliary used to build the perfect tense/aspect in French.^[6]
I have seen the sun = 'I have seen the sun/I saw the sun.'
g. Nous sommes hébergés par un ami. – être, from which sommes is inflected, 'be' is an auxiliary used to build the passive voice in French.^[7]
We are hosted by a friend.
These auxiliaries help express a question, show tense/aspect, or form passive voice. Auxiliaries like these typically appear with a full verb that carries the main semantic content of the clause.