Learn English – “And to you” or “you too”

As another American EE, I would use "mains" only in certain contexts...

After the hurricane, the hospital powered life support equipment from diesel generators for 36 hours, then switched back to the mains.

"Grid" would also be acceptable.

If you're referring to 120VAC (RMS) without caring about source, the accepted U.S. industry-wide term is 'line voltage'.

1. Suasive is an adjective that, in Linguistics (Grammar), "denotes a class of English verbs, for example, insist, whose meaning includes the notion of persuading and that take a subordinate clause whose verb may either be in the subjunctive or take a modal."

2. Persuasive is an adjective as well, that means being "good at persuading someone to do or believe something through reasoning or the use of temptation: an informative and persuasive speech." OR "She was very persuasive!"

The difference, then, is that while the former denotes a grammatical class for verbs, the second is adopted the way you already know, with people, situations, etc.

EDIT NOTE: In the OED it says that a speech can be "suasive" but considering the OALD and my dictionary didn't have it, I supposed it was an old use or it fell into disuse. So I checked the Ngram on google and it confirmed what Billare said and what I was thinking.