1) Mother Tongue: language which a person has been speaking from childhood
Example sentences: 1) People should never forget their mother tongue.
2) Every mother tongue is unique in its own way.
2) Challenged: something that puts you to test
Example sentences: 1) I challenged him to fight with me.
2) I accepted the challenge with dignity.
3) Tickled: a light touch that makes you laugh
Example sentences: 1) My pet tickled the maid on her leg.
2) I tickled him under the ears.
4) Irritated: showing slight anger
Example sentences: 1) Reena was irritated by her class teacher.
2) The street dog irritated the old man.