þencan

Part of speech: verb
Verb type: irregular weak verb (1)
(p þóhte; p.p. (ȝe)þóht) 1. to think, meditate; to consider; 2. to intend, plan, have in mind (to do something) (also þincan, ðincan, ðencan)
Etymology
[Mod E THINKProt-Germ *þankjan; Goth þagkjan; O Fris thanka, thenza, thenka; O Sax thenkian; Dt denken OHG denken (Mod G denken); Icel þekkja]
Paradigm

4.2.1. (b) - 1st class weak irregular verbs

Some verbs of this type showed the assimilation of the consonant of the verbal stem and the suffix forming the past tense. This assimilation must have taken place already in the Proto-Germanic language. At least, it is attested in Gothic (cf Goth þagkjan (to think) – p tense sing þahta; waúrkjan (to make, do, work)– p tense sing waúrhta, etc).

I class
irregular
infinitive past tense singular
to seek, to look for sécan sóhte
to buy bусȝаn, bусȝеаn bohte
to think, meditate þencan þóhte
to think; to seem, appear þyncan þúhte

The anomalous form-building in other OE weak verbs of the first class (e.g. tellan ← *taljan) is attributable to the assimilative phonetic influence of the suffix -jan of the Prot-Germ weak verbs, causing the umlaut (a > æ > e) of the verbal stem vowel, resulting in tellan in pres tense stem. In the p tense forms of the same verb, due to the absence of the said suffix, there is preserved the original Anglo-Saxon vocalization (-ea-, -a-) of the verbal stem (vid below).

I class
irregular
infinitive past tense singular
to tell, narrate tellan tealde, talde