[误] She was keeping something to her father.
[正] She was keeping something from her father.
[析] "对某人隐瞒某事"要用"keep something from somebody"句型。
[误] He kept to repeat the word again and again.
[正] He kept repeating the word again and again.
[析] keep doing something为连续不断地做某事。有时可以与keep on doing something互换。它们的区别在于keep doing something意为该动作一直不停地在进行中，如： When the train started, she kept waving her hand. 而keep on doing something则表示该动作可能停停顿顿但却一直在进行中，如： He kept on making the same mistakes in grammar.