Sites I find useful, mostly linguistics databases.
Constructions and Semantics
- ValPal the Leipzig Valency Classes Project database
- WALS World Atlas of Language Structures
- Similar in some ways to WALS, though a bit clunky in the interface, Syntactic Structures of the World's Languages.
- APiCS WALS for Creoles
- STEDT Sino-Tibetan semantic maps
- CLICS Database of Cross-Linguistic Colexifications
- DatSemShifts database of semantic shifts
- The Concepticon (a collection of many types of 'Swadesh List')
- DiACL The Diachronic Atlas of Comparative Linguistics, a work in progress
Phonology and Phonetics
- A Survey of some Vowel Systems likely vowel inventories
- A guide to small consonant inventories
- PBase allophony database
- UPSID phonological inventory database
- World Phonotactics Database
- PHOIBLE, cross-linguistic inventory data from numerous sources
- SAPhon, South American Phonological Inventory Database
- Index Diachronica historical sound changes (Online version)
- Typological tools for field linguistics: Questionnaires
- Fieldwork elicitation guides from the Max Planck Institute for Psycholinguistics. Organized by year of publication, or use the word cloud at the left.
- John McWhorter's list of expressions underrepresented in language instruction
- Gary Shannon's syntax tests
These dictionaries are good for exploring historical semantic relationships, as well as giving ideas for polysemies and derivations.
- A Dravidian Etymological Dictionary
- Proto Wintun some basic background and sparse derivational morphology, but primarily a dictionary of reconstructions.
- A collection of Irish dictionaries. The interface makes convenient to go back and forth between languages.
- Mbula dictionary, a bit inconvenient to use, but very thorough.
- Ahtna Athabaskan Dictionary, most interesting by being organized by roots, so you can see how different senses are derived.