Exactly as Leon said. The sentence structure itself does not change the meaning, so if you had not used "the" versus "a" they would mean the same thing. And regarding tenses, if you meant present tense it would be "gives", and if you meant past tense it would be "gave". Good question, Everton.

There is only one difference in meaning between the two: In the first: "He give the boy a book", you are talking about any book as you have used "a", an indefinite article. In the second: "He give the book to the boy", you are referring to a particular book as you have used "the", a definite article. I should also mention that in English for the present tense you would say: He "gives", not He "give". If you were talking in the past tense you would say: He "gave"