How can I determine the SOV when the sentence is not have to indicate sometimes the object or the subject?

You're right, sometimes identifying the subject and object in a Japanese sentence can be tricky, especially when particles are omitted or the sentence structure is more complex. Here are some strategies to help you determine the SOV order:

1. Rely on Context:

 * Previous Conversations: Pay attention to the preceding conversation. Often, the subject or object will be implied or have been mentioned previously.

 * Situational Clues: Consider the context of the situation. For example, if you're in a restaurant, the subject of the sentence might be "you" (customer) even if it's not explicitly stated.

2. Identify the Verb:

 * The verb always comes at the end of the sentence. This is a fundamental rule of Japanese grammar.

 * Once you find the verb, you can start working backward to identify the subject and object.

3. Look for Particles (Even if Omitted):

 * は (wa): Often marks the topic or subject of the sentence, but it can sometimes be omitted in casual speech.

 * が (ga): Clearly marks the grammatical subject of the sentence.

 * を (wo): Clearly marks the direct object of the sentence.

 * に (ni): Can indicate location, direction, time, or the indirect object.

4. Consider the Natural Flow of the Sentence:

 * Listen to the intonation and rhythm of the sentence. Native speakers often use pauses and intonation to emphasize certain parts of the sentence.

 * Pay attention to the overall meaning and logic of the sentence. This can help you determine the most likely subject and object.

5. Don't Be Afraid to Ask:

 * If you're unsure, don't hesitate to ask for clarification. You can politely ask "誰ですか?" (Dare desu ka?) - "Who is it?" or "何をしますか?" (Nani o shimasu ka?) - "What do they do?"

Example:

 * "本読む" (hon yomu) - Literally "book read"

   * This sentence alone is incomplete and ambiguous.

   * However, if you hear this in the context of someone discussing their daily routine, you could infer that the subject is "I" (implied) and the object is "book."

Remember, even native speakers sometimes omit particles in casual conversation. By paying attention to context, identifying the verb, and using the other strategies mentioned above, you can improve your ability to understand and interpret Japanese sentences, even when the subject or object is not explicitly stated.

頑張ってください! (Ganbatte kudasai!)