1 only

2 merely

3 just

4 but

1 without any better option

2 to have to

3 to be forced to

1 merely

2 simply

3 only

4 but

1 if only

2 so long as

1 limited

2 finite

1 there is nothing the determined person can't accomplish (idiom)

2 persistence will overcome

1 can be understood, but not described (idiom, from Zhuangzi 莊子|庄子); mysterious and subtle

1 all we need is an east wind (idiom); lacking only one tiny crucial item

1 to seize every minute (idiom)

2 to make the best use of one's time

1 to know the first, but not know the second (idiom); only partial information