根据汉语意思完成英文句子，每空限填一词。
1. 他们通过学习语法来造句。
They learned to make sentences _____ _____ grammar.
2. 你可以去找王老师。他擅长解决这类难题。
You can go and find Mr Wang for help. He's good at _____ _____ this kind of problem.
3. 我确实不知道明天该做什么。
I really don't _____ _____ _____ _____ tomorrow.
4. 他害怕夜晚独自出去。
He's _____ _____ _____ _____ alone at night.
5. 我哥哥总是尽力帮助我的学习。
My brother always _____ _____ _____ _____ help me with my studies.