I took it out once but besides that I had it in my pocket the whole time.
It was in my pocket but I took it out for a second.
❶ I took it out once but besides that I had it in my pocket the whole time.
(一回は取り出したけど、それ以外はずっとポケットにちゃんといれてたよ)。という意味です。
❷It was in my pocket but I took it out for a second.
(ポケットに入ってたけど、一瞬手に持ったんだよね)。
例えば:
Why was your phone not in your pocket?
(なんで携帯をポケットに入れてなかったの？)
It was in my pocket but I took it out for a second. That’s probably when I lost it. ( ポケットに入ってたけど、一瞬手に持ったんだよね。多分その時に失くしたんだ)。
I had it in my pocket the whole time, but I was holding it for a second and that's when I lost it.
この場合、次のような言い方ができますよ。
ーI had it in my pocket the whole time, but I was holding it for a second and that's when I lost it.
「ずっとポケットに入れたのに、少しの間手に持ってたら、その時に失くしちゃった」
to have ... in one's pocket で「…をポケットに入れておく」
to hold「手に持つ」
to lose「失くす」
ご参考まで！
アメリカ合衆国 
カナダ 
