posted by Mai .
I saw a young girl (stealing, stole, steal, steals) something from the shop.
which answer should it be and why?
"stealing" - a participle, not a complete verb, so it cannot serve as the main verb of a sentence unless you put a helping verb with it (is, are, will be, etc.).
"stole" - past tense, not correct in the sequence of tenses here because the main verb is in past tense (saw).
"steal/steals" - these are the present tense forms, which is what's needed in this subordinate clause; "steal" is the singular form and is used when the subject is singular; "steals" is the plural form and is used when the subject is plural. So ... what's the subject of THIS verb, and is it singular or plural?
You have 2 choices.
Here is one of the best sites to explain verbals. Look at the explanations for infinitives (to steal) and gerunds (stealing)to best understand why: