A place word does not determine its particle alone
Words such as school, station, and library describe places, but the sentence can relate to those places in different ways. You can go to a station, be at a station, or buy something there. Ask Mocchi to keep the noun constant while changing the event. This prevents the exercise from becoming a memory test of which particle happened to appear next to a word in your first textbook example.
Use verbs you understand. If the verb is unfamiliar, you may not have the information needed to choose the relationship. Ask for its meaning in a short phrase, then return to the particle decision. This keeps a vocabulary gap from masquerading as an unexplained grammar failure.
Compare three roles with one familiar place
学校に行きます makes the school a destination. 学校にいます locates the speaker at school. 学校で勉強します places the studying activity there. All three can be understandable beginner examples, but they ask different questions about the place. Explain those roles before moving to more complicated sentences with unfamiliar vocabulary or multiple clauses.

| Japanese | Romaji | Meaning |
|---|---|---|
| 学校に行きます。 | Gakkō ni ikimasu. | I go to school. |
| 学校にいます。 | Gakkō ni imasu. | I am at school. |
| 学校で勉強します。 | Gakkō de benkyō shimasu. | I study at school. |
Use a reason before checking the answer
After selecting a particle, state the relationship in one short sentence: the action happens there, the person exists there, or the place is the destination. If your reason does not match the event, ask Mocchi to explain the mismatch. A correct answer with an incorrect reason is a useful warning that the next example may still cause trouble.
Mix the roles after supported practice
An exercise that announces 'these are all destination sentences' removes part of the decision. Once the first examples are clear, ask for a mixed set and read each verb before answering. Change the places too, but keep the vocabulary manageable. This gives you practice recognizing which relationship is present rather than simply repeating the particle used in the previous question.
Save the exact contrast you still need
If you confuse existence and action location, name that pair in your review request rather than asking to study particles in general. If you only miss destinations with unfamiliar verbs, target those phrases first. Mocchi's learning context becomes more useful when the review note identifies a decision that can be tested in a fresh sentence. Later, study other uses of に and で as separate targets instead of assuming that this place-focused routine explains them all.

