What is the difference between"Was, -ed and verb2"
Which's correct?
I was think,I thinked,I thought

Question

What is the difference between"Was, -ed and verb2" 
Which's correct?
I was think,I thinked,I thought

Answer

Use your dictionary for irregular verb forms.

think | θɪŋk |
verb (past and past participle thought | THôt | )

Answer

For past tense, only use "was" with adjectives.
Today I am happy.
Yesterday I was happy.

For verbs, use verb2
I am running now.
I ran yesterday.

We DO occasionally put "was" in front of a verb, but that is a much more advanced structure called "passive voice."
I ate  the apple yesterday.
The apple was eaten yesterday.

Answer

'think' is an irregular verb.  So there is no '-ed' version of it.   Think - Thought

Answer

You cannot say "I was think" or "I was thinked", in fact the word "thinked" doesn't even exist, you can say "I was thinking". "I thought" is okay.