One pair of confusing adverbs is 总算 (zǒngsuàn) and 终于 (zhōngyú). They both can be translated as "finally" or "in the end," but they subtly different in tone.
Grammatically, 总算 and 终于 are basically used the same way. They are both adverbs, and they can be placed before the subject or after the subject. However, in comparison to 终于, 总算 is seldom used before the subject. But in these sentences given below, they can be replaced with each other.
Subj. + 总算 / 终于 + Verb
Both 总算 and 终于 express that an action has finally happened after a long wait, however 总算 implies that the speaker had a bit of an agonizing wait, and it has a heavier tone better suited to complaints.
终于 is more formal than 总算 (in other words, 总算 is more for spoken Chinese), and it also has a more objective feel (meaning that there was indeed a long wait for this thing that finally happened).