1. How to express “How long...”!!!
The verb HABER &
How to express “How long...”!!!

2. The Verb HABER
1. Used as an conjugated helping verb in all perfect tenses.
Present perfect: he hablado
Pluperfect: había hablado
future perfect: habré hablado
conditional perfect: habría hablado
Present perfect subjunctive: haya hablado
Imperfect subjunctive: hubiera hablado

3. The Verb Haber
As an impersonal expression meaning “There is” “There are”. It is always used in the 3rd person SINGULAR.
presente: hay (there is, there are)
pretérito: hubo (there was, there were)
imperfecto: habia (same as pret.)
futuro: habrá (there will be)
condicional: habría (there would be)
Subjuntivo: haya
Impf. Subjun: hubiera

4. Expressions to talk about the past
1. Something that was going on for a period of time when something else happened
Hacía + period of time + que +verb in the imperf.
As a question:
¿Cuánto tiempo hacia que + verb in the imperft.
To talk about how much time has passed since the action ended.
Hace + period of time + que + verb in the preterite
¿Cuánto tiempo hace que + verb in the preterite