The basic sentence structure must contain:

Subject ———————— verb ———————————— object

as simple as:
I love you, he is eating the chicken, Dahlia is reading a book.

According to thought co,the subject is usually a noun—a word that names a person, place, or thing. The verb (or predicate) usually follows the subject and identifies an action or a state of being. An object receives the action and usually follows the verb.

Credit to ESL Goal, the picture taken from eslgold.com/grammar/basic_sentence/ 

For more basic grammar, need to know more about nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions, and interjections.