ENGLISH TENSES- THE SIMPLE PRESENT TENSE

The simple present tense 

• Para expresar hábitos y rutinas, hechos generales, acciones repetidas o situaciones, emociones y deseos permanentes:
  I smoke (hábito); I work in London (permanencia); London is a large city (hecho general)
• Para dar instrucciones o indicaciones:
  You walk for two hundred meters, then you turn left.
• Para hablar de eventos programados, presentes o futuros:
  Your exam starts at 09.00.
• Para referirse al futuro, detrás de algunas conjunciones: after, when, before, as soon as, until:
  He'll give it to you when you come next Saturday.

¡Cuidado! El "simple present" no se utiliza para hablar de lo que está ocurriendo en este momento.

EJEMPLOS

• Hábitos y rutinas
  He drinks tea at breakfast.
  She only eats fish.
  They watch television regularly.
• Eventos y acciones repetidos
  We catch the bus every morning.
  It rains every afternoon in the hot season.
  They drive to Monaco every summer.
• Hechos generales
  Water freezes at zero degrees.
  The Earth revolves around the Sun.
  Her mother is Peruvian.

• Instrucciones o indicaciones
  Open the packet and pour the contents into hot water.
  You take the No.6 bus to Watney and then the No.10 to Bedford.
• Eventos programados
  His mother arrives tomorrow.
  Our holiday starts on the 26th March
• Construcciones de futuro
  She'll see you before she leaves.
  We'll give it to her when she arrives.

FORMACIÓN DEL "SIMPLE PRESENT": TO THINK

Afirmativa	Interrogativa	Negativa
I think	Do I think?	I do not think
You think	Do you think?	You do not think
He thinks	Does he think?	He does not think
She thinks	Does she think?	She does not think
It thinks	Does it think?	It does not think
We think	Do we think?	We do not think.
They think	Do they think?	They do not think.

NOTAS SOBRE LA TERCERA PERSONA DEL SINGULAR DEL "SIMPLE PRESENT"

• En la tercera persona del singular, el verbo siempre termina en -s:
  he wants, she needs, he gives, she thinks.
• Para las formas negativa e interrogativa, se emplea DOES (= tercera persona del auxiliar 'DO') + el infinitivo del verbo.
  He wants ice cream. Does he want strawberry? He does not want vanilla.
• Verbos que terminan en -y : en la tercera persona del singular, se cambia la -y por -ies:
  fly --> flies, cry --> cries
  Excepción: cuando una vocal precede a la -y:
  play --> plays, pray --> prays
• Añadimos -es a los verbos que terminan en:-ss, -x, -sh, -ch:
  he passes, she catches, he fixes, it pushes

EJEMPLOS

• He goes to school every morning.
• She understands English.
• It mixes the sand and the water.
• He tries very hard.
• She enjoys playing the piano.

Intenta resolver el siguiente ejercicio 

Put the verbs into the correct form.

1. I (to like)  lemonade very much.
2. The girls always (to listen)  to pop music.
3. Janet never (to wear)  jeans.
4. Mr Smith (to teach)  Spanish and French.
5. You (to do)  your homework after school.

Fuente: https://www.ef.com.mx/recursos-aprender-ingles/gramatica-inglesa/simple-present/

             https://www.ego4u.com/en/cram-up/tests/simple-present-1