[Grammar] He is willing to invest once I have decided

[shibli.aftab]

He is willing to invest once I have decided.

He is willing to invest once I decide.


What are the differences in the meaning of above sentences?

 

[Barb_D]

Not much.
With the first, the decision might be a bit further in the future.
But it does leave the reader wondering "decide what?"

 

[shibli.aftab]

Not much.
With the first, the decision might be a bit further in the future.
But it does leave the reader wondering "decide what?"

I want to learn a bit extra about these types of construction. It would be very nice if you explain it's grammar.
Thanks

 

[Barb_D]

I want to learn a bit extra about these types of construction. It would be very nice if you explain its grammar.
Thanks

I don't know what else to add.
You can switch the order, but if you do, put a comma after the time-dependent part:
Once I decide which restaurant I want to go to for my birthday, my husband will be happy to take me.
Once I have decided which restaurant I want to go to for my birthday, my husband will be happy to take me.