Understanding Simple Present Tense
Simple present tense is a verb form most commonly used in the English language which is used to reveal the factual events and habitual (customs), general and non-general, instruction, or plan or schedule.

 Formula Simple Present Tense
The formula for the simple present tense sentences positive, negative, and interrogative following example can be seen in the table below.Type of Formula Sample Sentences Simple Present Tensepositive (+) S + / - aux. verb (do / does) + V-1 She likes eating out.My friend cares about my problems.S + be (am / is / are) He's a magician.The children are naughty.negative (-) S + aux. verb (do / does) + not + bare infinitive She does not like eating out.My friend does not care about my problems.S + be (am / is / are) + not He is not a magician.The children are not naughty.interrogative (?) aux. verb (do / does) + S + bare infinitive Does she like eating out?Does my friend care about my problems?be (am / is / are) + S Is he a magician?Are the children naughty?Note:

    On the positive, the auxiliary verb is not normally used. Aux. verb is used only when necessary to emphasize the necessity to take action verb.
    Verb-1 on the subject in the form of third-person singular pronoun (she, he, it) or noun, add s or es.
    Bare infinitive is a V-1 in the form of a simple (no extra s or es for the subject though the third person singular).
    Be used is a linking verb.

 Examples of Simple Present Tense
Some examples of the simple present tense functions are as follows.Examples of Simple Present Tense FunctionsSimple present tense is used in habitual action (action that occur repeatedly) using the adverb of adverb of frequency or number. He always consumes low GI rice.(He's always eating low GI rice.)She sends money to her parents much in the village every month.(She sent money to her parents in the village every month.)Simple present tense is used to give instructions or action series. You add a glass of coconut milk into a pan and then boil it.(You add a glass of milk into a saucepan and boil.)You go straight ahead then turn left.(You go right ahead and then turn left.)Factual (general truths / facts are irrefutable) The sun rises from the east and sets in the west.(The sun rises from the eastern horizon and sets in the west.)Water boils at 100 degrees Celsius.(Water boils at 100 degrees Celsius.)Simple present tense is used in the general action (occurring at any time: past (in the past), present (current), and future (future)) except for the verb can be no general action. [General: occur anytime]She is so beautiful.(She is very pretty.)[Not general: happening now]He's angry.(He's mad.)Simple present tense is used to talk about a plan or schedule in the future but it has a period close to the present. Generally talking about transportation or event. Verb used include: arrive, come, and leave. The ship leaves the harbor this night at 7 o'clock.(The ship left the port this evening at 7.)He arrives from Osaka at 1 pm.(He arrived from Osaka 1 pm.)The ceremony starts at nine.(The ceremony begins at nine.)Simple present tense is used in the if conditional type 1. If you meet the naughty boy, your parents will be angry.(If you see that bad boy, your parents will be upset.)I will go swimming if I have free time.(I will go swimming if there is time.)
Read also an adverb of Frequency & Number on the Simple Present Tense. Hopefully useful and apologize if there are shortcomings. If you have questions, comments, or suggestions, you can leave it in the comment box below :).