What it means
つもりで expresses acting with the intention of doing something or acting while assuming that something is true. With a dictionary-form verb, it usually describes an intended action or plan. With a past-form verb, it means acting as if the action had already happened or assuming that it happened. With a noun followed by の, it means acting while assuming that one is that person or thing. It often connects this assumption or intention to a real action.
Usage note
つもりで is not the usual way to state a simple plan by itself; use つもりだ for that purpose. The polite versions are made by changing the sentence ending, while つもりで itself remains unchanged.
How to use it
初心者のつもりで、説明書を最初から読みました。
Assuming I was a beginner, I read the instructions from the beginning.
来年、日本へ留学するつもりで、毎日日本語を勉強しています。
With the intention of studying in Japan next year, I study Japanese every day.
海外旅行に行ったつもりで、地元の料理を作りました。
As if I had gone on an overseas trip, I cooked local food.
初心者のつもりで、説明書を最初から読んだ。
Assuming I was a beginner, I read the instructions from the beginning.
来年、日本へ留学するつもりで、毎日日本語を勉強している。
With the intention of studying in Japan next year, I study Japanese every day.
海外旅行に行ったつもりで、地元の料理を作った。
As if I had gone on an overseas trip, I cooked local food.
Example sentences
旅行に行ったつもりで、そのお金を新しい机の購入に使った。
With the idea that I had gone on a trip, I used that money to buy a new desk.
編集者になったつもりで、文章の誤りを探している。
I am looking for errors in the text as if I had become an editor.
初めて来たつもりで、館内の案内