Irregular 'IR' Verbs: Spelling Changes 'GUIR'-'G'
Spanish: Cambridge International GCSE, topic 10.6.19
Spelling Changes 'GUIR' - 'G'
IR verbs that end in 'guir' change their spelling to preserve the 'g' sound. They won't need the ‘gu’, only the ‘g’. Seguir is also a stem irregular verb in the present tense, also in the subjunctive present tense.

Siga - I continue

Sigas - you continue

Siga - he/she continues / you continue (formal)

Sigamos - we continue

Sigáis - you continue (plural)

Sigan - they continue (formal plural)
Test yourself on Irregular 'IR' Verbs: Spelling Changes 'GUIR'-'G'
Which of the following is NOT in the present subjunctive in Spanish?
How do you say 'I continue' in the present subjunctive in Spanish?