Since has two main meanings in English. It can show a starting point in time, or it can give a reason. The meaning depends on the sentence and the context.

Since can mean from a starting time until now or until another time. It names the beginning of a period, not the length of the period. It is often used when an action or state continues.

Since is often used with the present perfect when a situation started in the past and continues now. This pattern connects a past starting point to the present. In simple English, this is a common time use of since.

Since can help answer a question about how long something has continued by giving the starting point. In this use, the question asks about duration, but the answer with since gives the beginning. For duration itself, English often uses for instead.

Since can also introduce a reason or explanation. In this meaning, since is close to because. This use is common in simple sentences and the context shows that it is about cause, not time.

Sometimes since is clear, but sometimes the sentence can feel less clear without context. Native speakers may understand since as time or as reason, depending on the situation. You can now use since to show a starting point in time and to introduce a reason in simple English.