I had taken an expedition

[keannu]

Without any related past context, can you say "I had taken"? I think "have taken" is better. If this was said in past context, it would make sense.

kk130)I had taken an expedition to photograph wild animals in Africa.

 

[emsr2d2]

I'm not sure what you mean by "without any related past context". Do you mean without specifying a particular past period of time? If so, no.

A simple statement without any time period would read "I have taken an expedition ..."

 

[keannu]

Yes, I mean like this.
...Back then, I decided to make a great challenge. So I had taken an expedition to photograph wild animals in Africa. After that, I tried to deliver my message about the experience to others....

Without this kind of past context, how could you say so? That sounds quite awkward.

 

[emsr2d2]

Yes, I mean like this.
...Back then, I decided to make a great challenge. So I had taken an expedition to photograph wild animals in Africa. After that, I tried to deliver my message about the experience to others....

Without this kind of past context, how could you say so? That sounds quite awkward.

It sounds awkward because it is.

"Back then, I decided to take on a great challenge. So I took an expedition to photograph wild animals ..."

There is of course a possibility that "had taken" could be incorporated into your context.

"Back then, in 2001, I decided to take on a challenge. I had taken a trip to Africa some ten years earlier, and I [had] enjoyed it so much I decided to do it again in 2002, but this time I challenged myself to photograph every wild animal native to the African continent."