Spanish Cognate Rules by Ending
There are a number of rules on word endings that will make it easier to associate English words with their Spanish cognates or vice versa. Although these rules are not applicable in every single case, they can be taken as general guidelines for understanding cognates in Spanish and English. It should be noted that these rules are only applicable to the specific word form (i.e. verb, noun, adjective, etc.) indicated in the description of the rule.
Add -ar or -ir
English nouns ending in -al are often identical to their Spanish equivalent.
vowel+consonant + T -> tar or tir
Drop -e and add -ar or -ir (infinitive verbs)
Spanish Words that end in –ar are usually the same in English.