过去将来时时间标志词总共有多少个？

过去将来时时间标志词总共有四个：by the time, before, until, and by. 1. By the time: This time phrase indicates that an action will be completed before a specific moment in the future. For example, "By the time you arrive, I will have finished cooking dinner." It shows that the action of finishing dinner will be completed before the person arrives. 2. Before: This word is used to indicate that one action will occur prior to another action in the future. For instance, "I will clean the house before my guests arrive." It expresses that the cleaning will be done prior to the guests' arrival. 3. Until: This time expression denotes that an action will continue up to a specific point in the future. For example, "I will wait until you finish your work before we leave." It conveys that the waiting will continue until the work is completed. 4. By: By is often used to indicate a deadline for completion. For instance, "Please submit your report by Friday." It means that the report should be submitted before the end of Friday. These four time phrases are used to show the sequencing of actions in the future. The correct usage of these time markers helps in conveying the proper sequence and timing of events.