how to use " L' "
when i have to write in french about Le/La i can understand it.
but about L'

Question

how to use " L' "
when i have to write in french about Le/La i can understand it.
but about L' <

Answer

Use l' when the following word begins in a vowel sound, but not if it begins in a so-called "h aspiré."

Answer

Phil is absolutely right about L' before words starting with a vowel and H. As for choosing between LE and LA you have just to memorise it.