As we had seen that there is a change in the form of pronouns while adding preposition which is called सामान्य रूप (sAmAnya rUp) in Marathi.
Similarly, there is a change in nouns i.e. nouns also have सामान्य रूप (sAmAnya rUp) in Marathi. It also depends on the gender and the multiplicity of the noun.

The below table summarizes it.
If it the noun is not matching below rules then its सामान्य रूप is noun itself.

Gender
Singular form
Ending vowel
सामान्य रूप
(sAmAnya rUp)
in Marathi will end with
Singular Noun –
its सामान्य रूप
Example
सामान्य रूप
(sAmAnya rUp)
in Marathi plural will end with
Plural Noun –
its सामान्य रूप
Example
Masculineअ (A)
आ (A)
माठ - माठा
mATh– mAThA
e.g
pot - for pot
माठ - माठासाठी
आं (AM)
माठ - माठां
mATh –mAThAMsAThI
e.g.
pots - for pots
माठ माठांसाठी
Masculine
आ (A)/ ई ( I)या (yA)फळा - फळ्या
phaLA – phaLyA
e.g.
board - for board
फळा – फळ्यासाठी
पक्षी - पक्ष्या
e.g
bird – for bird
पक्षी - पक्ष्यासाठी
यां(yAM)फळे - फळ्यां
phaLe – phaLyAM
e.g.
boards - for boards
फळे – फळ्यांसाठी
पक्षी –पक्ष्यां
e.g
birds – for birds
पक्षी -पक्ष्यांसाठी
Masculine / Neuter
ऊस (Us)





ऊल (Ul)
वसा (vasA )





वला (valA )
पाऊस – पावसा
(pAUs - pAvasA )
e.g.
rain – for rain
पाऊस - पावसासाठी

पाउल - पावला
( pAul - pAvalA )
e.g.
foot – for foot
पाउल – पावलासाठी
वसां (vasAM)





वलां ( valAM)
पाऊस – पावसां
pAUs - pAvasAM
e.g.
rains - for rains
पाऊस - पावसांसाठी

पावले - पवलां
( pAvale – pavalAM )
e.g
feet – for feet
पावले - पवलांसाठी
Feminine
अ(a)
ए (e)





ई ( I)
माळ – माळे
mAL – mALe
e.g.
garland - for garland
माळ माळेसाठी

मांजर – मांजरी
(mAMjar - mAMjarI)
e.g cat – for cat
मांजर - मांजरीसाठी
(mAMjar – mAMjarIsAThI )
आं (AM)





ईं (IM)
माळा - माळां
e.g
garlands – for garlands
माळा माळांसाठी


मांजर - मांजरीं
e.g.
cats – for cats
मांजर - मांजरींसाठी
Neuterअ(a)/
ऊ (U)
आ (A)पान – पाना
pAn – pAnA
e.g.
leaf – for leaf
पान – पानासाठी
पिल्लू - पिल्ला
pillU - pillA
e.g.
chick – for chick
पिल्लू - पिल्लासाठी
आं (AM)पाने – पानां
pAne pAnAM
e.g
leaves – for leaves
पाने – पानांसाठी
पिल्ले - पिल्लां
e.g.
chicken – for chicken
पिल्ले - पिल्लांसाठी
Neuter
ए (e)
या (yA)
पाते -पात्या
pAte - pAtyA
e.g
blade – for blades
पाते -पात्यासाठी
यां
(yAM)
पाती - पात्यां
pAtI pAtyAM
e.g
blades – for blades
पाती पात्यांसाठी

As we had seen in the previous section of plurals, for Feminine nouns ending with अ(a) there are two ways of creating a plural. Continuing same logic, for those words, there are two different “सामान्य रूप” one ending with ए (e) and other ending with ई ( I)

If it the noun is not matching any of the above rules then its सामान्य रूप is noun itself.
e.g Broom in Marathi is झाडू (jhADU). It is masculine ending with
ऊ (U). It is not mentioned in the above rule. So its सामान्य रूप is noun itself i.e. झाडू (jhADU).
e.g.

broom – for broom
झाडू – झाडूसाठी

As we had learned before List of few frequently used prepositions

Preposition in English
Preposition in Marathi
aboutबद्दल (baddal )
after
नंतर (naMtar )
aside
बाजुला (bAjulA )
beforeआधी (AdhI )
belowखाली (khAlI )
forसाठी (sAThI )
fromपासून / कडून (pAsUn / kaDUn )
in / at
(*Refer note below)
आत / त (At / t )
like
सारखा (sArakhA )
outsideबाहेर (bAher )
tillपर्यंत (paryaMt )
without
शिवाय (shivAy )

The “To” preposition is ला (lA ) for singular and ना ( nA ) for plural

e.g.
To chick ->पिल्लाला To chicken -> पिल्लांना
spear-> भाला (bhAlA ) it is masculine
To spear -> भाल्याला (bhAlyAlA) To spears -> भाल्यांना ( bhAlyAMnA )

Now see how the form changes will happen with a preposition is used along with pronoun and noun

e.g.
To his fort
fort -> किल्ला (killA)
to fort –> किल्ल्याला (killyAlA )
his fort –> त्याचा किल्ला
to his fort –> त्याच्या किल्ल्याला (tyAchyA killyAlA )

You can see that सामान्य रूप of त्याचा is त्याच्या
त्याचा
is masculine ending with आ (A) So as per above rules its form becomes त्याच्या
This way you can try creating sentences. There are many exceptions to the above rules, you will sense it as and when you will read more and more Marathi.

Another Style. Extension of above

As we had seen in the previous post, when the preposition is used with pronoun the words become त्याच्यासाठी (tyAchyAsAThI), तीच्यामुळे(tIchyAmuLe), त्यांच्यानंतर ( tyAMchyAnaMtar ), etc. As you can see there is च्या (chyA) in every word. Because of this, some people tend to use च्या( chyA ) before every preposition used with a noun.
e.g.
For fort -> किल्ल्यासाठी (killyAsAThI ) or किल्ल्याच्यासाठी (killyAchyAsAThI )
On bucket -> बादलीवर (badalIvar ) or बादलीच्यावर (badalIchyAvar)
Under table -> टेबलाखाली (TebalAkhAlI ) or टेबलाच्याखाली (TebalAchyAkhAlI )

Both ways are right, but try to use first way i.e. without adding च्या (chyA) to preposition

Note for preposition In/at

In the table, it is written as आत/त (At/t )
When you are using च्या( chyA ) with सामान्य रूप (sAmAnya rUp); we use word “आत(At)”
But if we do not use च्या( chyA ) then we just append “त(t)” to word form.
e.g.
In/At fort -> किल्ल्यात (killyAt ) or किल्ल्याच्या आत (killyAchyA At )
In/At bucket -> बादलीत (badalIvar ) or बादलीच्या आत (badalIchyAvar) etc.

For “at home” we generally say घरात (gharAt) or a special way as घरी(gharI).
So some people may ask; “what is the difference between “आत” and “ई”?
To be precise; “आत” is used to indicate position “inside” and “ई” is used to indicate preposition “at”
e.g.
Gold is buried inside home ->सोने घरात पुरले आहे. (sone gharAt purale Ahe.
Tomorrow I am at home -> उद्या मी घरी आहे (udyA mI gharI Ahe)
But you can find both forms used invariably.

In very few cases “वर”(var) is also used to indicate preposition “at”. There is no precise rule when people prefer “वर”(var). But as per my observation when they are giving not-so-precise information or indicating a surrounding they use “वर”(var).
e.g.
I saw John at the airport -> मी जॉनला एअरपोर्टवर/विमानतळावर बघितलं (mI j~onalA earaporTavar/vimAnataLAvar baghitalaM)
Ladies met at the village well -> बायका गावाच्या विहिरीवर भेटल्या (bAyakA gAvAchyA vihirIvar bheTalyA)
Children are playing at/nearby river -> मुले नदीवर खेळत आहेत (mule nadIvar kheLat Ahet)
So more you read Marathi you may get more examples.

I have started creating a list of Marathi nouns, their gender and plural forms and सामान्य रूप. List is uploaded as an excel sheet at
https://sites.google.com/site/learnmarathionline/home/nouns-gender-plural-and-forms-for-prepositions
Download the excel sheet to view it correctly.
The Excel sheet is not up-to-date. I will keep adding more and more nouns. So please check this link frequently to see newly added nouns.

[Update on 1st Feb 2015]
I Happy to announce my “Marathi Dictionary for Learners” app on Google Play.
It can be downloaded quickly from
https://play.google.com/store/apps/details?id=com.learnmarathi.dictionary

This dictionary provides all the details for every noun viz. gender, plural, saamanyrup.
At present this dictionary has 1105 English words and 1233 Marathi words. I will keep updating the app to add more and more words.
Still, it may happen that word you search is still not added. You may try the words “platform”, “action”, “collection” , “आदेश”, “आवाहन” , “सावली” to quickly test of this dictionary.
So I request you to download and install the dictionary and let me know your feedback.