Is this English sentence right ?

1. I have a gift for my friend.
2. I will give a gift to my friend.

How is above sentence grammatical ?
I don't understand yet a difference between 'for' and 'to'.
Can you help me ?
Thanks a lot.

Sentence 2 is about action. You are going to give it to your friend. The first sentence you can assume that you are going to give it to the friend since you have a gift, but there is no actual action in the sentence. I hope that makes sense

You have a gift for you friend. You bought it and you have it. So you are telling someone that you have it.

This one says that you WILL give a gift to your friend. You might not have bought the gift yet. You could have the gift now, maybe not. You just are saying what you plan to do.

Thanks for an answer.
But you not answer yet about a dissimilarity between 'for' and 'to'.
I want to know about a dissimilarity between 'for my friend' and 'to my friend'.
My American friend said, 'for' means the presently, and 'to' means the future.
Is that right ?

And I want to know about a dissimilarity between 'for me' and 'to me' as well.

My American friend said, English is a very easy language, if you are knowing its rules.
And he said, 'If English is not eay, a lot of people(70% of the world) would not use the language.'
' so, you also can speak English' ' don't give up ! '

"For" and "to" are neither present nor future tenses. Present and future tenses are generally used to only describe actions, also known as verbs. The words in these sentences that are considered present and future are the words "have" from the first sentence, and "will give" from the second sentence.

With that said, let's get back to the main subject. The difference between "for" and "to" are actually quite simple. "For" is a word used to describe to whom the gift will belong to. "To" is a word which generally describes a destination, such as when you go to work, or when you go to the store. In this case, the destination is the friend.

I know that this may be a bit difficult to understand for someone that is learning the language, but hopefully it will help you out. Good luck with further educating yourself in the English language.

Thanks so much !
Your reply will be a lot of help to me.
Have a good weekend !

The word to and for are prepositions explaination below. English is not easy because it not only has a lot of rules but exceptions to each of those rules.
Found at: http://www.arts.uottawa.ca/writcent/hypergrammar/p reposit.html
What is a Preposition?

A preposition links nouns, pronouns and phrases to other words in a sentence. The word or phrase that the preposition introduces is called the object of the preposition.
A preposition usually indicates the temporal, spatial or logical relationship of its object to the rest of the sentence as in the following examples:
The book is on the table. The book is beneath the table. The book is leaning against the table. The book is beside the table. She held the book over the table. She read the book during class. In each of the preceding sentences, a preposition locates the noun "book" in space or in time.
A prepositional phrase is made up of the preposition, its object and any associated adjectives or adverbs. A prepositional phrase can function as a noun, an adjective, or an adverb. The most common prepositions are "about," "above," "across," "after," "against," "along," "among," "around," "at," "before," "behind," "below," "beneath," "beside," "between," "beyond," "but," "by," "despite," "down," "during," "except," "for," "from," "in," "inside," "into," "like," "near," "of," "off," "on," "onto," "out," "outside," "over," "past," "since," "through," "throughout," "till," "to," "toward," "under," "underneath," "until," "up," "upon," "with," "within," and "without."

__________________
Just my humble opinion!