alone

Tom alone is coming. 只有汤姆要来。

Tom is coming alone. 汤姆将一个人来。

only

Only I kissed her last night. 昨晚只有我吻了她(即别人没吻她)。

I only kissed her last night. 昨晚我只是吻了她(即没干别的事)。

I kissed only her last night. 昨晚我吻的只有她(即没吻过别人)。

I kissed her only last night / last night only. 我只是在昨晚才吻了她(即其它时候未吻过)。

clearly

Clearly he didn’t say so. 显然他没有这样说。

He didn’t say so clearly. 他说得没有那么清楚。

before long / long before

Before long he got married. 不久他就结婚了。

That had happened long before. 那事老早就发生了。

for long / long for

We won’t stay for long. 我们不会久住。

He longs for friendship. 他渴望友谊。