The teacher encouraged the students to keep studying hard.
Tips
usage
Two common compounds. 勉励 means to encourage someone; 勉强 means barely managing, reluctant, or forced. The polite phrase 共勉 means 'let us encourage each other'.
Right strength radical, the indexing component, supplying the core idea: applying effort. To 勉 is to put out strength, whether striving oneself or urging others on. Same effort family as 努 and 劝.
Left 免 supplies the sound - miǎn with no tone shift. It contributes no core meaning here, though the idea of pushing past difficulty loosely echoes 'avoiding' failure. The same phonetic appears in 晚.
