I often hear these mistakes made by German speakers who are learning English.
They say: I was in London two times.
There are a couple of things wrong with this.
Firstly, we don’t say two times, we say twice. (Remember: once, twice, three times, four times, five times, one hundred times etc.)
Secondly, to native speakers it sounds like an incomplete sentence. I’m waiting for the ‘when’. When were you in London?
So, the correct sentence is:
I was in London twice last week / last month / last year.
(Alternatively you can say “I went to London twice last week / last month / last year.”)
Remember, if the ‘number of times’ in London is more important than the ‘when’ in London then say:
I have been to London twice. (Here it is irrelevant when this was; the number of times is the focus.)
Have fun learning English!
Louise