1. El horno está en la cocina.
The oven is in the kitchen.
2. El sofá está en la sala.
The couch is in the living room.
3. ¿Dónde están las sillas?
Where are the chairs?
4. Nosotros no estamos en la casa.
We are not at home.
5. Hay un lavaplatos en la cocina
There is a dishwasher in the kitchen.
6. Hay unos gabinetes en la cocina.
There are some cabinets in the kitchen.
7. El microondas está en la cocina.
The microwave is in the kitchen.
8. Tú estás en el jardín.
You are in the garden.
9. El patio está detrás de la casa.
The patio is behind the house.
10. Tú estás en la sala familiar.
You are in the family room.
11. No hay un sofá en la cocina.
There is not a sofa in the kitchen.
In 1, 2, 4, 7, 8, 9 and 10 is used the verb estar in the Spanish Present Tense Form matching the right conjugations. Recall that the Spanish simple present tense (el presente or el presente del indicativo) is used to talk about habitual actions, routines, things that happens in this moment or in the near future, universal truths, facts, hypotheticals, lapses of time, among other.
3 is given in the question form using the verb estar as well and matching the third-person plural, so the question asks for the chair.
5 refers to dishwasher (lavaplatos), so it is obvious that this is found in the kitchen.
6 refers to cabinets (gabinetes), so it is obvious that this is found in the kitchen.
11 refers to a sofa (sofá), so it is obvious that this is not found in the kitchen.