is an expression that functions very similarly to つもりだ
‘to intend to do’. The primary difference being that 予定（よてい） is a ‘plan’, rather than an ‘intention’. Due to this, 予定（よてい）
is used far more frequently for things that you have formal plans to do (like meeting a friend for lunch).
To use 予定（よてい）
, just attach it to the non-past form of a verb, or to a noun (after inserting の
I plan to go drink with my senpai tonight.
My break is planned to start from next week.
is not added after 予定（よてい）
, it will imply that 予定（よてい）
is simply modifying the verb/noun that comes before it, rather than being a standalone ‘plan’. This is similar to the difference between saying something like ‘I have plans to eat with a friend’ (natural), vs ‘I have an eating with a friend plan’ (unnatural).
I have plans to eat a steak with a friend tomorrow. (Natural Japanese)
I have an ‘eating a steak with a friend’ plan tomorrow. (Unnatural Japanese)