Answer

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.