Have been

rashid rajal1.I have been a doctor for 3 years. Is that mean I am still doctor or its not doctor anymore.

It means that you have been a doctor for three years up until the present time. With no further information, it would normally be understood that you are still a doctor and will continue to be a doctor. With additional information, it could mean that you a

Thanks.
I have worked in different companies since 1980/ for 36 years.

Is this correct. It means it was past and not sure about present.

rashid rajalI have worked in different companies [since 1980/ for 36 years].

Correct.

rashid rajalIt means it was past and not sure about present.

Yes. More or less. It started in the past (36 years ago, to be specific) and has continued up to the pres

So.
I have been working since 1980.
I have worked since 1980.
And
I have been working for 3 years.
I have worked for 3 years.
Are these have same meanings or not.

rashid rajalAre Do these have the same meanings or not?

They have the same general meaning. They have different meanings in the small details. Those with "working" emphasize continuous activity over a period of time more than t

Thanks.
Some times it makes me confused. Here I will give an example.
1.I was in U.S. I spent there 10 years. Now I am in Uk.
I have lived in U.S for ten years.
Is that correct?
2. I had lived in US for 10 years .
Is that means I am not in US any longer.
Please explain.

rashid rajal1. I was in the U.S. I spent there 10 years there. Now I am in the UK.

Your need this: "I lived in the U.S. for ten years."

I don't recommend "have lived" in this case because there is a time gap between the end of the 1

Thanks alot . The way you make me understand is really great. I appreciate.
I have another thing that i need to know.
1.since I am working here I have been sick or I have been feeling sick.
Are these correct?
2.Some times we use " since" to mention a reason i think.
How we use that? Please explain.

rashid rajal1.since I am working here I have been sick or I have been feeling sick.Are these correct?

You need a point in time with "since", so you need this: I have been feeling sick since I started working here.

Also, reversing the order of the clauses, Since I started working here I have been feeling sick.

ras

"since" is just like "because" its comes start of sentence unlike "because" i got it.
help me with below one,
1. Since he has been or had been (or I can use both) a doctor .he had been helping people.
2. since he has been or had been a doctor ( or i can use both) he had helped people
here it is past perfect . can i use present perfect with "since" in start or only past perfect.