1. Right
es segura
The word es is a conjugation of the verb ser. We use the verb ser to talk about permanent or lasting attributes. In this way, this verb stands for descriptions, occupations, characteristics, time, origin and relationships. Since motocicleta is a feminine singular adjective, the adjective segura is also feminine singular. Recall that Spanish adjectives must agree with the noun or pronoun they describe in both number and gender. Finally:
Tengo miedo. Creo que la motocicleta no es segura
2. Right
estoy lista
Since the speaker of this sentence is a woman, the adjective used here must match the feminine singular form, that's the case of lista. On the the other hand, estoy is the conjugation of the verb estar for the first person singular in the simple present. Finally, this sentence can be written as follows:
Yo ya estoy lista para salir. ¿Y Miriam?
3. Right
Es muy larga
The verb ser here is being used as description, that talks about the essential qualities that describe a person or things. In this sentence, the thing that is being described is a movie, which is is boring and very long. This is a negative sentence, so negation is an expression that means no and is used to contradict some or all of the meaning of a positive sentence. Finally:
No me gusta la película. Es muy larga y aburrida.
4. Right
están
Están is the conjugation of the verb estar for the third person plural in the simple present. We use the verb estar to indicate temporary states and locations. In this way, this verb stands for position, location, action, condition, and emotion. Here we use it as location, describing where the passports is temporarily. Finally:
¿Dónde están nuestros pasaportes?
5. Right
está sucia
Here we use the verb estar as conditions, expressing that the room can vary from a state of dirt to cleaning, over several hours or days. So está is the conjugation of the verb estar for the third person singular in the simple present. So la habitación matches the third person singular. Finally:
La habitación está sucia
6. Right
es
We also use the verb ser to tell the time. If you want to refer one o'clock use es. On the other hand, to refer all other hours use son. Both are conjugations of the verb ser. This sentence use the formula a + la(s) + time to say a meeting occurs at a specific time. Finally:
La reunión con la agente de viajes es a las cuatro de la tarde
7. Right
es pequeña
This sentence matches the third person singular. So we need to use the conjugation of the verb estar that matches this person, which is es. We are using this verb here as description, talking about the size of a suitcase, which is an essential quality. Finally, the sentence can be written as follows:
Mi maleta es pequeña
8. Right
está
Here está matches the third person singular and recall that this word is a conjugation of the verb estar. Here I want to know where the door is. So this verb is acting here as location, describing where the door is permanently. Finally, this question can be written as follows:
¿Dónde está la salida?
