"slid" is already past tense. The present tense is "slide".
slid is the past tense
The past tense of "slide" is "slid."
slid
They slid.
Slid is already the past participle of slide. It's also the past tense.
The past tense of "slide" can be either "slid" or "slidden."
You may say "she slid across the ice" or "he had slidden all the way down the hill"
The past tense of backslide is backslid.
No, it is not. It is the past tense and past participle of the verb to slide. It can be a verb form or, very rarely, an adjective (e.g. slid bottle caps will pass under the door).
The most likely verbs could be FELL or SLID - both are past tense.(slipped would be redundant)
The past tense of slide is slid, and the past participle is also slid.
The present perfect tense of slide is "have/has slid." For example, "She has slid down the hill many times."