Irregular verbs

[Fazzu]

I want to know if I can say:

I have worn this dress before.(OR must I use 'had' instead of 'have'?)
I have wore this dress before.(I have no idea if this sentence is correct)

It's difficult for me to use irregular verbs and I don't know when I'm suppose to use them.Any help?

[Humble]

Hello Fazzu,
Irregular verbs are those that have their own forms II and III (the Past Simple and Past participle). If a verb is irregular it will have its II and III forms in brackets in dictionaries:
wear (wore, worn)
Regular words just add -ed in these forms: look (looked, looked). They are called regular, because they all change their forms according to the rule.
If you're dealing with a verb and you are not sure how to use it in, say, the Past Simple or Past Perfect, look up in a dictionary - if there are no other forms indicated - it's a regular verb.
Best wishes

[inezrufus]

Hi Fazzu,
In this particular instance you will need to say "I have/had WORN this dress before"

[Fazzu]

Oh thats a nice suggestion Humble.Thanks.By the way,may I know which one of my sentence is right?Also,why must I use 'begun' with 'I had' and not 'began' since 'began' is a simple past and is there any standard difference between past simple and past participle?

Thanks Inezrufus.So in my first sentence I can use any,'have' & 'had'?