Some other Indo-European languages do have a similar approach. In Russian, for example, there's this approach:
"U menya ['est] kniga" ("by me there is a book" = "I have a book")

However, I suspect that "le livre est à moi" does come from the French language's Celtic substrate, and I don't think it's necessarily true that there are no other features than just the two you mentioned which might have a Celtic origin. For example, compare "Il n'y en a que trois" with "Níl ach trí acu ann" ("There are not but three of them" = "There are only three of them").
The "not but" approach is also a very common way of saying "only" in parts the South (in the US), where there also some other turns of phrase of possible Gaelic origin. What is especially interesting about comparing the French and the Irish versions is the occurrence of the "en" and the "ann", in addition to the basic "not but" structure.

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I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

"I am but a man is perfectly valid English, albeit somewhat archaic. That structure may be a Celticism in English, but not necessarily.

Consider that "I am but" is probably a reduced form of "I am nothing/naught but"... one word dropped. What word might be dropped in the French? And right enough, a longer phrase exists with "rien" -- nothing: "il n'y a rien que". Less common these days, certainly, but I've heard it in songs, and Google brings is up in a book on French Renaissance literature:

Now there's an even longer form still:
"il n'y a rien en plus que"
and if we go back to "I am nothing/I have nothing" then you've got
"je n'ai rien en plus que Google et Bing comme moteur de recherche" (genuine example)

This structure has a direct parallel in Spanish
"No tengo nada más que"
...even if this mostly appears on the internet in translations of what English speakers said "I have nothing but respect for".
Still I've verified it against the Corpus del Español and of the four hits for "no tengo nada más que" in the 1800s and 1900s, two are followed by nouns "no tengo nada más que ese trabajo" (I have nothing more than this job) and "no tengo nada más que esperanzas" (I have nothing more than hopes/expectations).

So again, it's not out of character with a related language, and again, we'd have to include Spanish in our Celtic substrate group (which many would, but this particular theory doesn't).

Also, it's the y, not the en, that's equivalent to "ann" -- both equivalent to the "there" in English "there is...". en is the equivalent to "acu", but if you go beyond this structure, you'll find this is a coincidence, because for example the equivalent to "there are trois of us in my family" is "nous sommes trois dans la famille" -- the en has disappeared, and in fact the whole "il y a" has disappeared. Meanwhile I believe Irish would retain the acu, and the structure wouldn't change, with the "in the family" bit replacing the "in it" (that's how it works in ScG, anyway).

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A language belongs to its native speakers, and when you speak it, you are a guest in their homes.
If you are not a good guest, you have no right to complain about receiving poor hospitality.

Yes, I speak French, so I knew that. However, It has always struck me that en is a strange form for "of it/them" (rather than some form like "d'eux"), and I wonder about its etymology, since it is written and pronounced the same as the word en meaning "in". Perhaps there was a shift in meaning, with the "en" having originally been cognate with the Irish ann (or being from a similar substrate form) and then being reinterpreted as the "of it/them" part of the phrase, similar to the way that "ne ... pas" (for "not") evolved from an older form meaning "not a step", and now in popular French the word "pas", once being just the "step" part of the phrase, can mean "not" all by itself, without the "ne" even being used, as in "y a pas".

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I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

I imagine what you're talking about is - je ne marche pas where the second part of the negative was expressed according to the meaning intended ex: je ne mange miette, je ne bois goutte, though there was and still is the other negative word - point. (I seem to remember Alan Titley saying in his History of Gaelic that the Irish brought punctuation to the rest of us in Europe - point à la ligne). Would there be an equivalent in Irish for this kind of thing? I don't know. Similarly I'm a bit uneasy about looking for direct parallels between the way Irish and French function. I agree 'en' does have this meaning of 'in it', 'of it' and 'it being there' but whether it has anything to do with 'ann', I am very dubious about that. I can give you of one example of a parallel that did strike me I first started learning Irish and that's the way possession used to be expressed in old French. Here are some examples of what I mean - Droichead an Easpaig - Pont l'Evèque, Baile na Banríona - Bourg la Reine, queue le leu - eireaball an faolchú - but is that a more general example of how European languages function? It's not easy to say. Not long ago there was an important exhibition put on in Paris about les Gaulois with some amazing archaeological finds on show and there was one part of the expo devoted to the Celtic linguistic heritage in modern French. It was about vocabulary and place names, but not really anything to do with expressions or the way Gaulish could have influenced later French usage.
www.cite-sciences.fr/francais/ala_cite/ ... s/gaulois/
There's also the website of the Centre National de Ressources Textuelles et Lexicales www.cnrtl.fr that you might like to look at - is there an Irish equivalent of that?
There was one other example of a shared tradition, though no longer known in France, that I gave a long time ago at the other place, when we were talking about the tradition of the Wren boys - Dreoilín, Dreoilín Rí na nÉan - where the wren in French is called the 'little king' - le roitelet.
http://rupestres.perso.neuf.fr/page0/pa ... 81-182.pdf - Jean-Loïc Le Quellec

Highly, highly unlikely.

For one thing, Italian has a partitive pronoun ne which functions pretty much exactly like the French en. The forms are similar enough to be most likely of a single origin. I'm not aware of what the current theorised origin is, but for it to be a Celtic "ann"/"yn", you're then suggesting that the usage spread back to Tuscany from French before the consonant flipped across to the other side of the syllable. Now Corsican also has ne (or ni in the south) and while it ultimately derives from an early form of Tuscan, the split occurred a very long time ago.

French has also undergone much more change than Italian from the Roman forms, so it's most likely it started out as something closer to ne than en, and that subsequently, the French negative stole the ne pronunciation, forcing the partitive pronoun to change in parallel. Would the commoners still be speaking a Celtic tongue by the time this change occurred? I don't know. But still, the meaning of the partitive was clear and unambiguous, with the grammatical partitive ultimately deriving from Latin, and there's no evidence in the language that speakers got confused about its meaning (unlike in Iberia where there is no partitive pronoun), so the most likely explanation is simply arbitrary sound change.

_________________
A language belongs to its native speakers, and when you speak it, you are a guest in their homes.
If you are not a good guest, you have no right to complain about receiving poor hospitality.

The French pronoun "en" derives from the Latin "inde" - see https://archive.org/stream/etymological ... 8/mode/2up

Inde meant "from there, thence".

One highly likely explanation is that places named before French lost its genitive never gained a "de" when the change occurred (being considered "fixed phrases"), and that this established a new pattern that was just more convenient and still holds with street names and hotels.

_________________
A language belongs to its native speakers, and when you speak it, you are a guest in their homes.
If you are not a good guest, you have no right to complain about receiving poor hospitality.

Interesting, thanks.

_________________
A language belongs to its native speakers, and when you speak it, you are a guest in their homes.
If you are not a good guest, you have no right to complain about receiving poor hospitality.

Any of ye read this book? : http://www.amazon.com/The-Unfolding-Language-Evolutionary-Invention/dp/0805080120

'The Unfolding of Language'. It's provides a simple model for grammaticization due to sound changes examining mostly Arabic tri-consonatal roots but also some other languages. It's quite holistic in its approach and I found it fun

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__̴ı̴̴̡̡̡ ̡͌l̡̡̡ ̡͌l̡*̡̡ ̴̡ı̴̴̡ ̡̡͡|̲̲̲͡͡͡ ̲▫̲͡ ̲̲̲͡͡π̲̲͡͡ ̲̲͡▫̲̲͡͡ ̲|̡̡̡ ̡ ̴̡ı̴̡̡ ̡͌l̡̡̡̡.___

I agree. I too prefer to refer to them as "constrastive forms" rather than "emphatic forms".

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Múinteoir Gaeilge - Irish Teacher
My "specialty" is Connemara Irish, particularly Cois Fhairrge dialect, but I can also speak Ulster and Munster Irish with native-level pronunciation.
Is fearr Gaeilge ḃriste ná Béarla cliste, cinnte, aċ i ḃfad níos fearr aríst í Gaeilge ḃinn ḃeo na nGaeltaċtaí.
Gaeilge Chonnacht (GC), go háraid Gaeilge Chois Fhairrge (GCF), Gaeilic Uladh (GU), Gaelainn na Mumhan (GM), agus Gaeilge an Chaighdeáin Oifigiúil (CO).