some cases of plural and genitive case
Dear Irish speakers! :)
Help me, please!

How would you say the next things:

1. plural for “pasta” (Or it doesn't exist because “pasta” is a kind of matter?);
2. genitive case for pasta : a lot of pasta = go leor pasta?

3. plural for “sú talún”: “súnna talún”?
4. genitive case for “sú talún”: a lot of strawberry = go leor sú talún?

5. orange juice, apple juice, peach juice, tomato juice... = sú oráiste, sú úill, sú péitseoige, sú tráta?

Thank you!

Question

some cases of plural and genitive case
Dear Irish speakers! :)
Help me, please!

How would you say the next things:

1. plural for “pasta” (Or it doesn't exist because “pasta” is a kind of matter?);
2. genitive case for pasta : a lot of pasta = go leor pasta?

3. plural for “sú talún”: “súnna talún”?
4. genitive case for “sú talún”: a lot of strawberry = go leor sú talún?

5. orange juice, apple juice, peach juice, tomato juice... = sú oráiste, sú úill, sú péitseoige, sú tráta?

Thank you!

Answer

1, 2. "Pasta" could be considered either a 4th declension noun or a foreign word, in either case the genitive is the same as the nominative. Theoretically the plural would be "pastaí" but I think it's safe to say that it doesn't exist in real life (even in Italian the plural form of "pasta" is never used).
3, 4. There are two different nouns with the form "sú" in Irish; one is masculine and means "juice", it has the plural "súnna"; the other is feminine and means "a kind of berry" and it has the plural "sútha"; so the plural of "sú talún" is "sútha talún". Since "sú" (both meanings) is in the 4th declension it doesn't change in the genitive: "lots of strawberry" = "go leor sú talún"; "lots of strawberries" = "go leor sútha talún".
5. This is the other "sú"; your examples are correct, and together they would be "súnna" = "juices".