Is their any way to guess at a words plural form by the letters it contains ? Is their any clue as to what the plural form is in how it ends for example, or is it a case of having to learn the plural along with the word?

I hope im not gong over what is considered my fair share of questions on this board , Im just eager to learn.

Keep the questions coming.

Yes, it's very easy to get all the cases of words once you know what you're doing.

Think of how words in English ending in "ium" become "ia": stadium -> stadia, and how "ius" -> "ii": radius -> radii. Well that's how it works in Gaeilge, ie. there's special endings.

Here's the special endings:

bróg fuinneog Feminine
coinneáil fágáil Feminine
sionnach Masculine báisteach Feminine
múinteoir stáplóir Masculine
dochtúir Masculine
báicéir Masculine
codarsnacht Feminine
dornálaíocht Feminine
mainistir Feminine
teorainn Feminine
gadaí Masculine
madra bille (or any other vowel other than í) Masculine
bialann Feminine
féachaint Feminine

Go to An Foclóir Beag and type one of those words in and it'll show you all the cases.

Outside of those, you work with the last vowel.

dán
caisleán
béal
rothar
plúr
pobal

They all end with broad vowels, and as such, they're all masculine and worked with as so:

an pobal
na pobail
lár an phobail
lár na bpobal

And then you have slender vowels:

béim
páirc
fíric
feis
fail

they're all feminine and they're worked with as so:

an bhéim
na béimeanna
ionad na béime
ionaid na mbéimeanna


And outside of that, you just have plain old odd ones:

timpeall na tine
(You would think that tine is masculine, it ends in a vowel, but it ain't)

ainm mo charad ( cara becomes carad, no explanation!)

an t-ainm -> na hainmneacha

an oíche -> na hoícheanta
(not an exhaustive list)

Can I just say that this is a perfect example of what this board should be about , you have , due to your generosity of character and selflessnes , assured that not only will I continue in my endeavours to learn Gaeilge but that the time it takes me to get a grasp on the basics will be shortened.
thanks a million that was most helpful

this board rocks!!
translate that!

Mar choíche, tá fáilte romhat!

Regardless of what group a noun fits into, what ending it has or whatever, they all follow the rules of their gender. Even better, the gender difference only comes into play in the singular. The plural is universal:

na pobail Masculine
na béimeanna Feminine
na héisc Masculine
na hóicheanta Feminine

Rule: na neither cause séimhiú nor urú, but it sticks a h before a vowel

Plural Possesive Case:

lár na bpobal
cúis na mbéimeanna
ainmneacha na n-iasc
i lár na n-oícheanta

Rule: na + urú

And then we have the singular. Here, the genders are done differently:

Maculine

an pobal mór
lár an phobail mhóir

an t-óstán beag
ainm an óstáin bhig

an siúcra milis
údar an tsiúcra mhilis

Feminine

an bhialann mhór
lár na bialainne móire

an áit chairdiúil
ainm na háite cáirdiúla

an tsráid fhada
ainm na sráide fada

-

That's pretty much it! I learned them a good while back and they're second nature to me now, I took all that straight out of my head. Adjectives have a posessive case too... they're done just like the nouns though, and they also have their own groups:

an t-óstán cairdiúil
an áit chairdiúil

ainm an óstáin chairdiúil
ainm na háite cairdiúla


It's all just decoration.

Go n-éirí an t-ádh leat!