Question

he was too old to learn new things (use'so.....that ....)

Answer 1

hey mate!!!!!
___________

He was so old that he could not learn new things.

I hope it will help you.

Answer 2

Hey there!

In these types of sentences we change 'too' into 'so' and 'to' into that and we add 'not' if it isn't given in the sentence.

So, the answer will be:

He was so old that he couldn't learn new things.

Hope It helps You!