Some basic translations

Question

I'm a Russian boy and my grandfather was Italian and I've always wished to learn his mother language. I've tried so many times to learn Italian, but its grammar is so difficult to grasp for me.

After seeing the advices of Tim Ferriss at ted in this video I've decided to try it again. Can you help me with translation in Italian of the following 13 short sentences? Also, can you specify which are the grammar rules to apply for each sentence?

Grazie mille!

1. The apple is red.

2. It is John's apple.

3. I give John the apple.

4. We give him the apple.

5. He gives it to John.

6. She gives it to him.

7. Is the apple red.

8. The apples are red.

9. I must give it to him.

10. I want to give it to her.

11. I'm going to know tomorrow.

12. I can't eat the apple.

13. I have eaten the apple.

Answer 1

The apple is red can be rendered la mela è rossa; note that the English strawberries are red (meaning all strawberries) should be rendered le fragole sono rosse: the article is compulsory in this case. Your English sentence the apples are red is wrong unless there's a specification: the apples in that box are red.

English doesn't want the article when a possessive is around, but Italian does: it is John's apple becomes è la mela di Giovanni. Similarly, it's my apple is è la mia mela. The article is usually omitted when talking about relations: mia madre, mio zio, mio cugino.

In I give John the apple we find the “double object” which doesn't exist in Italian: do la mela a Giovanni.

I want to give it to her has a small quirk that's specific of Italian:

la voglio dare a lei
voglio darla a lei

are pretty much equivalent; in the second the emphasis is more on the pronoun la (meaning the apple), in the first the emphasis is more on a lei. Pronouns can be attached to the verb as suffixes (and sometimes they change form); in this case the verb can lose the final vowel, but the rules are complex: compare

da' la mela a me
dammi la mela

are alternative (the second is more frequent) and

serviti da solo (help yourself)

where no other form can be used.

Answer 2

The apple is red. La mela è rossa

It is John's apple. È la mela di John

I give John the apple. Do la mela a John.

We give him the apple. Gli diamo la mela

He gives it to John. La dà a John

She gives it to him. La dà a lui.

Is the apple red? La mela è rossa?

The apples are red. Le mele sono rosse.

I must give it to him. Devo darla a lui.

I want to give it to her. Voglio darla a lei

I'm going to know tomorrow. Lo saprò domani.

I can't eat the apple. Non posso mangiare la mela.

I have eaten the apple. Ho mangiato la mela.

Those are not literal translations. There is not correspondence univocally and the translation depends on the contests. About grammar: ask something more specific. There are a lot of rules to know and I don't know your level.