To be - the search for the Gaulish verb (part2)

I was curious about the Gaulish verb "to be", and I tried to work out the present, past and future tenses of it by comparing it to the tenses in Latin, Old Irish, and Welsh. I also started with the Gaulish words: immi, esi, buetid, esti, and biiete.

Present Tense
Latin
Singular.	Plural.
1. sum 2. es 3. est	1. sumus 2. estis 3. sunt
Old Irish
Singular.	Plural.
1. tau, to 2. tai 3. ta	1. taam 2. taid 3. taat
Welsh
Singular.	Plural.
1. ydwyf 2. ydwyt 3. ydyw	1. ydym 2. ydych 3. ydynt
Gaulish
Singular.	Plural.
1. immi, imi 2. esi 3. esti, buetid	?
Past Tense
Latin (Imperfect Tense)
Singular.	Plural
1. eram 2. eras 3. erat	1. eramus 2. eratis 3. erant
Old Irish
Singular.	Plural
1. ba, roba, raba 2. ba 3. boi, bai, robae	1. bammar 2. baid 3. batar
Welsh
Singular.	Plural.
1. bum 2. buost 3. bu	1. buom 2. buoch 3. buont
Gaulish
Singular.	Plural.
?	?
Future Tense
Latin
Singular.	Plural.
1. ero 2. eris 3. erit	1. erimus 2. eritis 3. erunt
Old Irish
Singular.	Plural.
1. bia 2. bic 3. bieid, bied	1. be(i)mmi 2. bethe 3. bieit, biet
Welsh
Singular.	Plural.
1. byddaf 2. byddi 3. bydd	1. byddwn 2. byddwch 3. byddant
Gaulish
Singular.	Plural.
?	1.? 2. biiete 3.?

Being that Latin is the closest in time and relationship to Gaulish, of the three languages, I thought that it would give me some clues about the tenses of Gaulish "to be". Latin didn't help much, though, so I also looked at the verbal endings for the regular verbs in Latin for the present, past and future.

Latin
Present Tense
Singular.	Plural.
1. -eo, a 2. -es, -as 3. -et, -at	1. -emus, -amus 2. -etis, -atis 3. -ent, -ant
Past Tense (Imperfect Tense)
Singular.	Plural.
1. -ebam, -abam 2. -ebas, -abas 3. -ebat, -abat	1. -ebamus, -abamus 2. -ebatis, -abatis 3. -ebant, -abant
Future Tense
Singular.	Plural.
1. -ebo, -abo 2. -ebis, -abis 3. -ebit, -abit	1. -ebimus, -abimus 2. -ebitis, -abitis 3. -ebunt, -abunt
Gaulish
Present Tense
Singular.	Plural.
1. -o 2. -as 3. -at	1. -omu 2. -etis 3. -ont

According to the Latin 1 grammar that I consulted "-ba-" indicates past tense, and "-bi-" indicates future tense. I also noticed that the Celtic examples also use the the same fomula, as Latin, in their past and future tenses of the verb "to be".
Example:

• Old Irish ba, bammar, bieid;
• Welsh buost, buoch, byddant;
• Gaulish buetid, and biiete.

According to Christopher Gwinn, biiete translates into "you (plural) all shall be", then maybe "bi-" is the Gaulish future indicator. Buetid was given as meaning "it is", but "esti" also translates into "it is".
I think that buetid means "it was", and that "bu-" is the Gaulish past indicator. Following this logic, these are the forms (*) of the Gaulish verb "to be" that I initially worked out:

Gaulish
Present Tense
Singular.	Plural.
1. immi, imi 2. esi 3. esti	1. *esumo 2. *esete 3. *esont
Past Tense
Singular.	Plural.
1. *bumi 2. *busi 3. buetid, *bueti	1. *bumo 2. *buete 3. *buont
Future Tense
Singular.	Plural.
1. *bimi 2. *bisi 3. *bietid, *bieti	1. *biumo 2. biiete, *biete 3. *biont

After consulting Christopher Gwinn, the corrected present tense forms of Gaulish "to be" are:

Gaulish
Singular.	Plural.
1. immi, imi 2. *esi(ti) 3. *est(is/si) rel. *est	1. *immu(s), *imme(s)i 2. *este-(suis) 3. *sent(i), *sint(i) rel. *sontio, *sontia

"Buetid" appears to be a compound verb. *Bueti + id ("it"). Personal pronouns are sometimes found attached to the third singular forms; probably to help distinguish between masculine, feminine, and neuter genders.

It appears that the present tense of Gaulish follows an irregular form, whereas the past and future tenses follow the regular verbal forms indicated by the two attested examples.

Gaulish
Past Tense
Singular.	Plural.
1. *buimi 2. *buesi 3. *bueti, *buieti	1. *buimu 2. *buete 3. *buont
Gaulish
Future Tense
Singular.	Plural.
1. *biimi 2. *biesi 3. *bieti	1. *biimu 2. biiete, *biete 3. *biont

Gaulish *buont has a cognate in Welsh buont. Both words have the same spelling, same tenses, and same meanings; in two P-Celtic languages - one ancient and one modern.
Gaulish *biont shows up in the "Plomb Du Larzac" inscription as biontutu(s).
The suffix "-utu(s)" indicates a subjunctive mood. That means, biontutu(s) translates into "if they will".
The passive voice is formed by adding the suffix "-or". Thus, this produces these forms of the Gaulish verb "to be":

Gaulish
Present Passive
Singular.	Plural.
1. *imior 2. *esior 3. *estor	1. *immusor 2. *esteor 3. *sentor
Past Passive
Singular.	Plural.
1. *buimior 2. *buesior 3. *buetior	1. *buimuor 2. *bueteor 3. *buontor
Future Passive
Singular.	Plural.
1. *biimior 2. *biesior 3. *bietior	1.*biimuor 2.*bieteor 3.*bintor, *biontor

A 3^rd Celtiberian form, robiseti, shows the prefix "ro-". This prefix also appears in Old Irish (roba), and imparts the perfect voice to a verb.
Verb forms without "ro-" indicate a narrative form.

Negative forms are made by adding ne ("not") + the verb.
Example: (Celtiberian) nebintor, (Old Irish) nim.
Interrogative forms are made by adding ne at the end of the verb. Example: (Old Irish) inn.

The 4^th Celtiberian form, cabiseti, shows the prefix "ca-". This prefix also appears in Old Irish (corrabe, corotaicciller). The prefix "ca-" imparts the meaning "until, or so that".
Cabiseti translates into "until you (plural) will".

As a summary I've tabulated the tenses on the next site.

As a summary I've tabulated the tenses here:

Gaulish Verb "To Be" verbal noun = es-, esse = to be, being
Present Tense Narrative Voice
Singular.	Plural.
1. imi, immi = I am 2. esi = thou art, you are 3. est, estsi, estis = he, she, or it is rel. est = he, she, or it is	1. immus = we are 2. este = you (all) are 3. sent = they are
Perfect Voice
Singular.	Plural.
1. roimi = I am 2. roesi = thou art, you are 3. roest = he, she, or it is rel. roest = he, she, or it is	1. roimmus = we are 2. roeste = you (all) are 3. rosent = they are
Passive Voice
Singular.	Plural.
1. imior = I am 2. esior = thou art, you are 3. estor = he, she, or it is rel. estor = he, she, or it is	1. immuor = we are 2. esteor = you (all) are 3. sentor = they are
Subjunctive Voice
Singular.	Plural.
1. imiutu(s) = if I am 2. esiutu(s) = if thou art, if you are 3. estutu(s) = if he, she, or it is rel. estutu(s) = if he, she, or it is	1. immutu(s) = if we are 2. esteutu(s) = if you (all) are 3. sentutu(s) = if they are
Negative Voice
Singular.	Plural.
1. nimi = I am not 2. nesi = thou art not, you are not 3. nest = he, she, or it is not rel. nest = he, she, or it is not	1. nimmus = we are not 2. neste = you (all) are not 3. nesent = they are not
Interrogative Voice
Singular.	Plural.
1. imine? = I am? 2. esine? = thou art?, you are? 3. estne? = he, she, or it is? rel. estne? = he, she, or it is?	1. immusne? = we are? 2. estene? = you (all) are? 3. sentne? = they are?
Forms with "ca-"
Singular.	Plural.
1. caimi = until I am 2. caesi = until thou art, until you are 3. caest = until he, she, or it is rel. caest = until he, she, or it is	1. caimmus = until we are 2. caeste = until you (all) are 3. casent = until they are
Past Tense
Narrative Voice
Singular.	Plural.
1. buimi = I was 2. buesi = thou wert, you were 3. bueti = he, she, or it was	1. buimu = we were 2. buete = you (all) were 3. buont = they were
Perfect Voice
Singular.	Plural.
1. robuimi = I was 2. robuesi = thou wert, you were 3. robueti = he, she, or it was	1. robuimu = we were 2. robuete = you (all) were 3. robuont = they were
Passive Voice
Singular.	Plural.
1. buimior = I was 2. buesior = thou wert, you were 3. buetior = he, she, or it was	1. buimuor = we were 2. bueteor = you (all) were 3. buontor = they were