"The taxi is here."
Translation:El taxi está aquí.
Estar is used for things that are temporary and not permanent. So, because the taxi isn't permanently 'there' it's estar rather than ser.
Está is used for location and condition.. Many people here quote 'no matter how you feel (emotions, feelings, temporary characteristics) and where you are (location) - that is when you use estár' it is catchy in my opinion ;)
[ Estar for how you feel, where you are, transient, temporary status · mnemonic acronym PLACE: Position, Location, Action, Condition, Emotion.] · contrastingly · [ Ser - Permanent status, use mnemonic acronym DOCTOR: Descriptions, Occupations, Characteristics, Time, Origin, Relationships ] · https://forum.duolingo.com/comment/24635443 · https://www.duolingo.com/comment/3732817/Overview-of-grammar-explanations · https://studyspanish.com/grammar/lessons/serest1.htm · https://studyspanish.com/grammar/lessons/serest2.htm http://www.studyspanish.com/lessons/serest3.htm · https://www.spanishdict.com/guide/ser-vs-estar ]
"El aeropuerto es aquí" will be correct because it is permanently there. "El taxi es aquí" is incorrect because it moves.
It's hard to find a grammatical paradigm with no exceptions, and this is especially true with those taught for Ser and Estar.
Estar is often taught as being used for impermanent actions or states of being, but this is not always the case; Estar is also used for location. The correct translation would be El aeropuerto está aquí; as, in this sentence está is describing the airport's location.
Similarly, we would write España está aquí, but we would write Madrid es la capital de España; in the first sentence, we are defining the location of Spain, in the second we are not — we are defining its relation to Madrid.
Just to help clarify, "es" is the he/she/you (formal) conjugation of the verb "ser". Which does mean "to be". However it is used for things that don't change. For example, "he is a boy" would be "él es un niño".
Estar is the verb "to be" for things that do change. Like in this question, "the taxi is here" so it would be "el taxi está aquí". It MUST have the accent in order for it to be the verb form.
Este/esta mean "this"
If you need more clarification then try reading the comments every time one of these comes up. There's a lot of helpful information.