We don't usually use "be" in present tense. Te meaning is clear from context. I am a student. --- Я студент. I am from America. --- Я из Америки. It's only true for present tense, in case of the future or the past "буду" и "был" are used accordingly.

Basically the phase "I am" could be translated into Russian like: "Я есть" (I - "я", am - "есть"). But in the sentence "I am a student" the verb "есть" usually is omitted. The same is with the phrase :"I am a human" (Я - человек), the english verb "am" is not used. The rule is used for such kind of sentences with "i" "you" "we" and so on. In the sentence "i am from Aremira" you should use the same rule, as i mentioned before and translate your sentence without the verb "есть" - "Я из Америки".

Всё очень просто: Я- I am Я студент.- I am a student. Я из Южной Америки.( или так: Я живу в Южной Америке.)- I am from South America.

Thanks you all! I was in doubt because of this omission of the verb

I think it easier in Russian than in English, just use "Я" and everyone in Russia will understand you correct. For example: I am a teacher (Я учитель) I am from ... (Я из ...) I am writing (Я пишу) I love you (Я люблю тебя) I go to school (Я хожу в школу) P.S. All this correct only for Present tense