Mixed tenses (I worked, I have worked, I have been working, I had worked)

The past simple is used to describe fully completed events in the past. We often use a time indicator (e.g. yesterday, last year, in 2003 etc) but we don’t always have to mention it – important is that the context must be about this past time, e.g.
I worked in Bremen yesterday.
He / She / It / We / You / They worked ….

We use the present perfect to talk about:
1. A current situation that started in the past
It connects a time in the present with the past. This is often in connection with the words “for” and “since” (if you think about the words, they always create a link to the past), e.g.
I have worked here for four years (I still work here!)
2. Past experiences where a time is not specified , e.g.
He has been to Berlin (no time given).

The present perfect continuous connects the past with the present and is often used with questions like: how long? ….. since when?
1. To connect the past with the present. We describe something which started in the past and is still correct today.
e.g. I have been working in the sales department for two years.
You can also use the present perfect simple to describe this action:
e.g. I have worked in the sales department for two years.
2. To describe something which has happened recently or lately and is still correct. The emphasis here is that the action is recent or late.
e.g. He has been working very effectively lately.
3. To describe a repeated event in the recent past:
e.g. I have been trying to call you for ages.

Remember! (see present continuous for more information)
The continuous is normally only used with action verbs, e,g, We have been working on the report all morning.
It can sometimes be used with state verbs, e.g. We have been having dinner for ages.

We use the ‘past perfect’ to describe an action in the past, which occurred prior to another completed action.
Key words are: before and after.
It is useful to use the ‘past perfect’ when the order of action is unclear and it is then necessary to emphasise and define which action happened first.
It is often used in conjunction with the ‘past simple’.
e.g. I had worked (1) in England before I moved (2) to Germany.
action (1) = past perfect
action (2) = past simple