eng learning

(moved here)
had an interesting lecture last nite talking about verb phrases but this is not the interesting part as wht our prof said linguistics boring… yes he did say it but not in class.. :P he said it when he drove me to the station
the most interesting part is to know that hk students can hardly do past perfect correct it’s surprising too how come? prof said according to a research survey done by the eng dept they interviewed many (the number was not told) cuhk stds and found out that the most difficult part in learning eng is tenses [my NB: the #1 difference between chi and eng is tense n thus i always wonder if the scholars deliberately set the questionnaire leading to the intended result; of ‘coz this shouldn’t be the case but i wonder why not prepositions the most difficult?] and the weakest part in their eng is past perfect!!!!! i supposed it was the 'big' group covering both simple and continuous.
prof he showed two examples (remeber they are wrong english!) that most hk stds did / wrote (quoted from prof he; i'm not sure and in fact i doubted)
i visited cuhk when i arrived shatin
i had dinner after i arrived home
so as prof he said strictly speaking they were wrong in both sentences a 'had' was missing before 'arrived'
n he spent a few min in explaining the time line time point n why it should be part perfect
strange... simple past perfect should be a 'clear enough tense'... how about future perfect? personally i think they're "related"... if u get the concept of 'perfect' well, there shouldn't be any problems in understanding past and future perfect.... but not present perfect.. present perfect has other meanings and usage...
english is a tense language with 12 tenses (so far as i've learnt)
to make it simpler... let's say the timeline has pt. a b c d and e, and now is at pt. d;
basic rule is:
simple past perfect is a; past is b but u have to explicitely mentioned the pt. b when u use the tense; present perfect is c; simple present is d, future is e, any action has not yet happened but planned to happen before a future reference point (e.g. e) is future perfect.
these are the basic six tenses without continuous. when putting continuous to them... we formed 12 tenses.
are they so difficult?
i remember i learnt these in primary school, but not the whole 12 tenses.
we should have learnt 9 in details without great details in the perfect continuous.
the whole 12 tenses were further explained in great details during the junior high school
i remember i once saw my friend's notes from the tutorial centre, A1 or A in A, they also detailed ALL 12 tenses!!! so it shouldn't be sth. strange to hk stds... can i conclude that?