For vs For up to // Get by in (a language) vs Can get by in (a language)
I came across this sentence in a book:

...where teenagers live in an all-English environment for up to four weeks at a time.

(Is there any difference between "for" and "for up to"?)

Can you use "can get by" and "get by"?

When I was doing an exercice to rewrite somes sentences I came across this:

I speak enough German for holidays. (get by)

First I wrote: "I get by in German on holidays", but in the Answer Key was "I can get by in German on holidays".

Can I use both?

Thank you in advance!

Question

For vs For up to // Get by in (a language) vs Can get by in (a language)
I came across this sentence in a book:

...where teenagers live in an all-English environment for up to four weeks at a time. 

(Is there any difference between "for" and "for up to"?)

Can you use "can get by" and "get by"?

When I was doing an exercice to rewrite somes sentences I came across this:

I speak enough German for holidays. (get by)

First I wrote: "I get by in German on holidays", but in the Answer Key was "I can get by in German on holidays". 

Can I use both?

Thank you in advance!

Answer

I can get by = you have the ability to get by (you might not do it for some reason)

get by = you have the ability and DO get by

For 3 years = a period of time that is 46 months

For up to 3 years = a period of time 46 months or less

Answer

"For four weeks at a time" = every time a person goes, he or she stays four weeks.
"For up to four weeks at a time" = When a person goes, he or she can leave before the four weeks is up,but can stay the full four.

I get by in German on holidays = You have already been to Germany on holiday and have gotten by with your German.
I can get by in German on holidays = Implies a holiday yet to come - you have the ability to get by if it happens.

Đừng bỏ lỡ cơ hội học ngoại ngữ ngay tại nhà. Hãy xem danh sách các gia sư ngôn ngữ giàu kinh nghiệm của chúng tôi và đăng ký buổi học đầu tiên ngay hôm nay!