Is there a name for words that exist purely for syntactic reasons and carry no lexical meaning?
Some forms of sentence in my language don't have verbs, but information such as tense and mood are indicated by affixes on the verb. So, in cases where you need to modify the verb, a meaningless verb fills in; the verb carries no meaning on its own, existing just to hold affixes.
Here is a sentence without a verb. No verb is used for just applying an adjective to a noun. Adjectives are applies directly to the noun.
The wood is alive.
But (for example), past tense is marked by a suffix on the verb so it needs a verb to attach onto; ta "stands in" for the absent verb, giving -to (past tense) something to attach to.
The wood was alive.
"Ta" is the word I'm talking about.