For, since, ago and before ➲ A for ➲ We use for to say how long something continues: We swam for quite a long time ➲ B for and since with the present perfect We use for to say how long something has continued. HOW LONG for a year ➲ We use since to say when something began. WHEN since half past six ➲ C ago with the past We use the adverb ago to talk about a past time measured from the present: I passed my driving test a month ago.

For, since, ago and before (II) ➲ D for, since and ago Compare these three sentences: they all describe the same action: for: I've had this bike for six months. since: I've had this bike since May. ago: I bought this bike six months ago ➲ E before with the past perfect We use before (not ago) with the past perfect. I bought a car in August. I'd passed my driving test three months before.