Expressing Duration and Ago

1. tener/llevar + period of time + gerund
e.g. Tengo/Llevo nueve años trabajando aquí. -> I’ve worked here for nine years.

2. hacer + period of time + que + present indicative
e.g. Hace tres años que vivo aquí. -> I have lived here for three years.

3. present indicative + desde hace + period of time
e.g. Vivo aquí desde hace tres meses. -> I have lived here for three months.

4. For duration up to a past moment, use the imperfect indicative.
e.g. Hacía tres años que vivía allá. -> I had been living there for three years.

Expressing how long ago something happened

hace + period of time + preterit
e.g. Comí hace dos horas. -> I ate two hours ago.