Opening is the present participle of open.
You open / You are opening.
It is a noun
I/You/We/They open. He/She/It opens. The present participle is opening.
Only if you use was or were with it egI was opening the door when the phone rang.They were watching Tv last night.
No... that is called a weak verb.
The present perfect tense of shake is have/has shaken.I have shakenWe have shakenYou have shakenHe/she has shakenThey have shaken
If you mean "to notice" in the past tense, it would be "noticed". Here's an example sentence: Last week I noticed a sign for the new karaoke bar that is opening up on main street.
The word opened is a verb. It is the past tense of the verb "open".
Take a deep breath.
Am, is, and are are present tense forms of be. The past tense forms of be are was and were. The future tense of be is will be.
Past tense I had Present tense I have Future Tense I will have
The past tense of did is did. The present tense of did is do. The future tense of did is will do.