Indicates something has not yet happened or is still happening; 'still', 'not yet'.
まだ + Verb (in non-past, negative non-past or te-form), まだ + い-adjective, まだ + な-adjective + じゃない/ではない, まだ + Noun + じゃない/ではない
Long explanation:
The まだ〜 grammar point is used to express that something has not yet occurred or is still in progress. It can be translated as 'still' or 'not yet' in English. Depending on the context or if expressing the negative, 'まだ' can be used with different combinations of verb, adjective or noun.