It would be much clearer that the statement is a temporary situation if you used the while preposition:
While David is studying in the USA he will not come back very often.
While David is studying in the USA he won't come back very often
'While' shows that the situation is expected to come to an end.
Alternatively, you could use since to mark the ...
From the website lexology.com, 4/20/19:
 After success against Comcast with an earlier action at the ITC [the International Trade Centre], TiVo is once more seeking an exclusion order as it looks to hurt its rival’s cable platform.
Looks with with complement the active infinitive to hurt, and the infinitive taking the object platform. ...
"Completion" can mean two things:
The fixed point at which something is completed. This cannot be ongoing - something either is or is not complete.
The final stage of something. This can be ongoing if you are currently in that final stage of completion.
Your first sentence is fine:
The construction work will be completed in two months.
This uses my ...
"Prices are increasing" means that currently prices are increasing over time, there is a gradual change happening.
"Prices increase" would mean that it is a characteristic of prices to increase, it is a general truth.
"Prices have been increasing" means that it has been happening for a period of the time, from the past until this moment.
"Prices have ...