Contribution/ Originality: This study contributes in the existing literature of English teaching. The present study is one of very few studies which have investigated synonym teaching strategies in the light of social constructivism

Synonym/antonym race
Divide your students into two teams and ask one person from each team to come to the board. Decide if you are going to practise synonyms or antonyms. Then say a word, for example, ‘say’, and see which team can come up with a synonym or antonym first. The first team which writes their word down correctly will get a point. Then invite two new players to the board and play another round with the same word. When students run out of synonyms for ‘say’, you give them a new word. 
Split crossword
This is one of my favourite activities that can be easily adapted for teaching and revising both synonyms and antonyms. In split crosswords students work in pairs and explain words from their half of the crossword to each other. This is, for example, what one part of such a crossword looks like:
Instead of asking students just to explain the words, you can add a twist to that and tell them to use one-word antonymic explanations. If they have to explain ‘talkative’, they can go like ‘quite’ – or ‘reticent’, ‘taciturn’, ‘silent’, depends on the level. The same task can be done with synonyms.
Write 3, pass around
Have a list of target vocabulary scattered around a piece of paper. Hand out one copy for each student. Ask them to write down synonyms or antonyms for any 3 of the words given and then pass the paper to some of their group mates. They repeat till there are no words left on the paper. 
After the activity is over, you can look through the answers open class and choose the most original or the rarest synonyms. Also, you can compile a list of them and ask students to write it down or to use in some follow-up activity. 
This activity involves cooperation and is quite stress-free even for low level or struggling students. As they choose the words themselves, they can pick up the ones they know and feel more confident about. Also, they can spot some new word and copy it while working with the next piece of paper. 

CONCLUSION

This paper has made an exploration of synonym teaching in senior high schools under the guidance of social constructivism. It is based on the situation that teachers and learners have not paid enough attention to the synonym teaching and learning. Meanwhile, teachers still lacks of practical teaching strategies. In this situation, this paper gives a comprehensive introduction to the definition and classification of synonym. Based on social constructivism, we have proposed three principles and teaching strategies for the synonym teaching. It is hoped that these teaching strategies will be of great help to promote English synonym teaching in senior high schools. Owing to the lack of time, energy, teaching experiences and so on, this paper has some limitations. The teaching strategies need to be further explored in teaching practice. Furthermore, researchers should explore more applicable theories, together with social constructivism, to guide the synonym teaching.