Joint Workshop on Multiword Expressions and Electronic Lexicons (MWE 2021)

In Bangkok, Thailand Online with ACL-IJCNLP 2021

Endorsed by SIGLEX.

17th Workshop on Multiword Expressions (MWE 2021)

Colocated with ACL-IJCNLP 2021 (Bangkok, Thailand Online), 6 August 2021

Organised and sponsored by:
Special Interest Group on the Lexicon (SIGLEX) of the Association for Computational Linguistics (ACL)


Multiword expressions (MWEs) are word combinations which exhibit lexical, syntactic, semantic, pragmatic and/or statistical idiosyncrasies (Baldwin & Kim 2010), such as by and large, hot dog, pay a visit and pull one's leg. The notion encompasses closely related phenomena: idioms, compounds, light-verb constructions, rhetorical figures, institutionalised phrases, collocations, etc. The behaviour of MWEs is often unpredictable, in particular their meanings are not regularly composed of the meanings of their parts. Thus, MWEs are a major challenge in computational linguistics (Constant et al. 2017), including linguistic modelling (e.g. treebanking), computational modelling (e.g. parsing), and end-user NLP applications (e.g. natural language understanding, machine translation, and social media mining).

Modelling and processing MWEs for NLP has been the topic of the MWE workshop organised by the MWE section of SIGLEX in conjunction with major NLP conferences since 2003. Although much progress has been made in the field, MWE processing in end-user NLP tasks is currently under-explored, and most studies still introduce MWEs as future work. Nonetheless, there are recent studies in which MWEs gained particular attention in end-user applications, including machine translation (Zaninello & Birch 2020), text simplification (Kochmar et al. 2020, Liu & Hwa 2016), language learning and assessment (Paquot et al. 2019, Christiansen & Arnon 2017), social media mining (Maisto et al. 2017), and abusive language detection (Zampieri et al. 2020, Caselli et al. 2020).

The special focus for this 17th edition of the workshop is on MWE processing in end-user applications such as those listed above. On the one hand, the PARSEME shared tasks (Ramisch et al. 2020, Ramisch et al. 2018, Savary et al. 2017), among others, fostered significant progress in MWE identification, providing datasets, evaluation measures and tools that now allow fully integrating MWE identification into end-user applications. On the other hand, NLP seems to be shifting towards end-to-end neural models capable of solving complex end-user tasks with little or no intermediary linguistic symbols, questioning the extent to which MWEs should be implicitly or explicitly modelled. Therefore, one goal of this workshop is to bring together and encourage researchers in various NLP subfields to submit MWE-related research, so that approaches that deal with MWEs in various applications could benefit from each other.

Following the success of previous joint workshops LAW-MWE-CxG 2018, MWE-WN 2019 and MWE-LEX 2020, we further extend the scope of the workshop to MWEs in e-lexicons and WordNets, MWE annotation, as well as grammatical constructions.

The 17th Workshop on MWEs invites submissions on (but not limited to) the following topics:

Traditional MWE topics:

Topics on MWEs and end-user applications:

Joint session with WOAH Workshop

Pursuing the MWE Section’s tradition of synergies with other communities and in accordance with ACL-IJCNLP 2021’s theme track on NLP for social good, we will organise a joint session with the Workshop on Online Abuse and Harm (WOAH). We believe that MWEs are important in online abuse detection, and that the latter can provide an interesting testbed for MWE processing technology. The main goal is to pave the way towards the creation of data for a shared task involving both communities. The format of the session is under discussion, and we welcome suggestions from the community. Submissions describing research on MWEs and abusive language, especially introducing new datasets, are also welcome.

Important dates

All deadlines are at 23:59 UTC-12 (anywhere in the world).


The MWE workshop is organized by the SIGLEX-MWE section.

Program committee


For any inquiries regarding the workshop please send an email to

Please register to SIGLEX and check the “MWE Section” box to be registered to our mailing list.

Anti-harassment policy

The workshop supports the ACL anti-harassment policy.