I have been in England since last week
is this the present perfect or present tense
and if you could please, explain the perfect and present tense?
thank you
I dont have much need to classify verbs in this way myself, but I dont see how it can be present anything, as the meaning is in the past, and the "been" bit of the phrase shows us ... you probably need a good text book for the other bit of your question, I cant help!
I think the names foreign learners of English give to the tenses are perhaps a bit different than those native learners are taught in schools.
At any rate, 'I have been...' is the tense I know as 'present perfect'. It denotes something that happened or started in the past but it or its effects still go on in the present.

'I have always thought it's not true' = at some point in the past I started thinking it's not true, and I still think that.

'I have known her for years' = I got to know her some time in the past and I still know her.