THE PRESENT PERFECT WITH for AND since

Spanish people find it difficult to produce correct sentences using rhe present perfect with FOR or SINCE because they tend to translate literally from Spanish into English.
Pay careful attention to the following examples in English and their  Spanish translation and remember that we use the past simple for complete finished actions or states that belong entirely to the past and we use the present perfect for actions or states that started in the past and continue up to  the present.

I bought my car last August-

Me compré el coche el pasado Agosto.

I bought my car 8 months ago.

Me compré el coche hace 8 meses.

I have had my car for 8 months.

Tengo el coche desde hace 8 meses / hace 8 meses que tengo el coche.

I have had my car since last August.

Tengo el coche desde agosto.

Note that
-  we use FOR for periods of time and SINCE for a point in the past
- with simple past Spanish "hace..." is AGO and with present perfect is FOR
- in Spanish we use simple present when translating this kind of present perfect.

I met Mark in 1916 at my sister’s wedding

Conocí a Mark en 1916 en la boda de mi hermana

I met Mark 3 years ago.

Conocí a Mark hace 3 años.

I have known Mark for 3 years.

Hace 3 años que conozco a Mark / Conozco a Mark desde hace 3 años

I have known Mark since 1916 / since my sister’s wedding

Conozco a Mark desde 1916 / desde la boda de mi hermana

We got married last year.

Nos casamos el año pasado

We got married a year ago.

Nos casamos hace un año.

We have been married for a year.

Llevamos un año casados / hace un año que estamos casados..

We have been married since last year.

Estamos casados desde el año pasado.

I moved to London in 2006.

Me mudé a Londres en 2006.

I moved to London 18 years ago.

Me mudé a Londres hace 18 años.

I have lived in London for 18 years.

Vivo en Londres desde hace 18 años.

I have lived in London since 2006

Vivo en Londres desde 2006.