Tra từ however - Từ điển American Heritage Dictionary 4th

how·ev·er (hou-ĕvʹər)adv.
1. In whatever manner or way:
However he did it, it was very clever.
2. To whatever degree or extent: “have begun, however reluctantly, to acknowledge the legitimacy of some of the concerns” (Christopher Lasch).
3. In what way. Used as an intensive of how:
However did you get here so soon?
4. In spite of that; nevertheless; yet:
The book is expensive; however, it's worth it.
5. On the other hand; by contrast:
The first part was easy; the second, however, took hours.conj.
1. In whatever manner or way:
Dress however you like.
2. Archaic. Notwithstanding that; although.
Usage Note: Although some grammarians have insisted that however should not be used to begin a sentence, this rule has been ignored by a number of reputable writers. Forty-two percent of Usage Panelists say they do not follow the rule in their own writing, 19 percent say they observe it only sometimes, and 36 percent say they usually observe it. See Usage Note at but. See Usage Note at whatever.