I know that slid is the past tense of slide, but what if ou want to use the word 'has' in front of it? Isn't it a different word then?

The boy has slid towards home base and came up short.

'Has' was not necessary in the sentence.

The boy slid towards home base and came up short.

Hence, slid can be past or present tense. There is no such word as slidden.

There is no such word as slidden.

Actually, there is: past participle of slide, though it's considered archaic usage (http://dictionary.reference.com/browse/Slidden&)today.

Actually, there is: past participle of slide, though it's considered archaic usage (http://dictionary.reference.com/browse/Slidden&)today.

I stand corrected.

I know that slid is the past tense of slide, but what if ou want to use the word 'has' in front of it? Isn't it a different word then?

Due to new information, let me rephrase part of my answer.

There is no word "Slidden" in the English language based on what is considered modern usage.