Conversation between two friends:
A: Hey, John, how tall is your son?
B: well, he has become this high.(showing with his hand)
Two cute little kids are talking about their tv:
A: Our new TV is this big. (showing with two hands)
B: Our TV is that big. (pointing his finger at a cupboard)
Are the set of words natural in sopken English?
Thanks in advance.
The bold part of all of your examples is correct and idiomatic.
Note that we only use the word become when describing a change of state or degree, for example:
Your son will soon become a man - a change of state, from boy to man
Cars have become become more streamlined over the past 30 years - a comparison between how things were,and how they are now
Describing your son's height is not a change- you are simply saying how tall he is now- so you just say
well, he is this high. (showing with his hand)
