1. Pres. Perf. Simple (HAVE/HAS + PARTICIPLE)
Pres. Perf. Continuous (HAVE/HAS + BEEN + V-ing)
Both the Pres. Perf. Simple and the Pres. Perf.
Continuous are used to express that an action began in the
past and is still going on or has just finished.
But there is often a difference in meaning:
• We use the Pres. Perf. Simple mainly to express that an
action is completed or to emphasise the result (what / how
much / how often):
• I have written 5 letters. = (the letters are already written)
• I have been to London twice. = (now I´m at home)
• We use the Pres. Perf. Continuous to emphasise the
duration or continuous course of an action (how long):
• I have been writing for an hour. = (up until now)
• I have been doing my homework. = (up until now)

2. PRES. PERF. SIMPLE PRES. PERF. CONTINUOUS
Ever
Never All (day, week, …)
Already For
Just Since
Still This week, year, …
Yet
Recently