"since" means "from", before a time word, like 从, but it has to be a time in the past. "until" and "till" are the same. They mean "to", before a time word, like 到. "He has been sleeping since 8 o'clock." 他从8点起在睡觉呢。 "He will sleep until 8 o'clock." 他到8点会睡觉。 Sorry if my Chinese is bad. :)

since -- shows the moment of beginning till -- shows the moment of ending

"Since Monday" means that the action BEGAN Monday (in the past). "Until Monday" or "Till Monday" means that the action will END Monday (in the future). "Till" and "until" are the same, but "till" can only be used in a very informal context. Pham Son Tung's first example is not correct. It should be: "I've been learning English since 2010." More examples: - It has been raining since yesterday. (It started raining yesterday, and it is still raining.) - It will rain until tomorrow. (It is raining, and the rain stop tomorrow.) - It won't stop raining until tomorrow. (Same meaning. This construction is common: I won't ___ until ___.) - I've spoken German since I was young. - Obama has been president since 2009. - Obama will be president until 2017.

"Since" means from a particular time in the past until the present, or in that of period time. And "till" has the same meaning with "until". If sth happens until a particular time, it continues and then stops at that time For example: - I've learn English since 2010. (That means I began learning English at 2010, and now I'm still learing English. Here we just know about the time that sth begins happening) - I'll wait till you come or I'll wait until you come. (That means we don't know about the time that the action begins, we just know that, when "you come" the action "wait" will stop) Hope it would help you a little bit.