We use the adverb 始终 to emphasize the action was happening the whole time.
We should put this adverb before the predicate which is expressed by a verb or a verb-phrase.
Examples
这个比赛始终很有意思
This contest was interesting from the beginning to an end
zhè ge bǐsài shǐzhōng hěn yǒuyìsi
我们尽力的话,能始终保持健康
If we try hard, we can always be healthy
wǒmen jìnlì dehuà, néng shǐzhōng bǎochí jiànkāng
If we state the negative particles 不 or 没 after the adverb 始终, it will be translated as “still couldn’t”.
Examples
我等了很久,但始终没等到
I couldn’t wait any longer even though I’d already waited for long time