Limiting with 〜だけ

だけ means “limit”. The word it appends to is given focus as the only one that something applies to.

Usage with particles

When the word marked by だけ is the subject, the が may be omitted. Likewise for the object and を. When not ommitted, だけ only appears before が or を, not after.

If the word marked by だけ has the particle で, だけ may appear before or after で. This also applies to に and と.

English

In English, だけ is often translated “only” or “just”. These make sense in an English translation, but a learner of Japanese should be aware that these translations obscure its meaning within a Japanese sentence.